bad 02 readings

[richardb200373]

So ideal reading is 0.45 volts for an 02 sensor right? Mine reads 0.13 on average. If I rev up the engine, it will go almost to 1.0 and drop back down. I replaced 1 (I have 2 on 2002 jeep 4.0L) but both still have the same reading. Why is it so low? Then engine is warm when testing. Any thoughts? Please help.


Ok, hold on, went and did another check. With my multimeter set on 20, on battery of course, reads 13.6v. On the 02 sensor, it fluctuates at 0.04 to 0.05, is it supposed to be 0.045 on the reading? I'm getting a little mixed up on this. Checking my efie to set it, it will go from 0.000 to 0.60, that is the furthest I've taken it. Someone please get me on the right path here, this is driving me freakin insane! One other thing, my engine light has been on forever, the codes lead to 02 and 0bd problems. I had the efie on with no hho as I was rebuilding. It was set on about 0.22. The other day the check engine light just went off. The minute I hooked HHO backup, it came on. I've been playing with the efie for a few days now and not getting any better, maybe a hair here and there.

[HiTechRedNeck73]

1st problem... you should make sure you car is running with no errors before installing an HHO device... otherwise you're chasing your tail trying to find the problem when a CEL does light up...

personally I think you guys are looking at the o2 sensors wrong... it's not a constant voltage that goes back to the ECU... it's a pattern... a wave pattern, and looks something like this:

http://www.supermotors.net/getfile/678893/fullsize/graph-o2volts-idle1.jpg

now this is an example... my car has 4 o2 sensors... on these charts, the top are sensors before the cat, and the bottom are after the cat... make one is on the left and bank 2 is on the right... for my car, you will notice that the sensors after the cats usually don't get higher than .25volts... where the ones before the cats range from below .25 and pulse up to 1.02...

the point to all of this is... you need to know what your vehicle does so you can mimic it... so the ECU truly thinks everything is "ok" and then you will not have as many problems...

I'm working on my cell, so I can't give any advice on your setup... but you should find out what your vehicle's sensors are saying to the ECU before you go changing it...

just my .02, hope it helps...

[H2OPWR]

So ideal reading is 0.45 volts for an 02 sensor right? Mine reads 0.13 on average. If I rev up the engine, it will go almost to 1.0 and drop back down. I replaced 1 (I have 2 on 2002 jeep 4.0L) but both still have the same reading. Why is it so low? Then engine is warm when testing. Any thoughts? Please help.


Ok, hold on, went and did another check. With my multimeter set on 20, on battery of course, reads 13.6v. On the 02 sensor, it fluctuates at 0.04 to 0.05, is it supposed to be 0.045 on the reading? I'm getting a little mixed up on this. Checking my efie to set it, it will go from 0.000 to 0.60, that is the furthest I've taken it. Someone please get me on the right path here, this is driving me freakin insane! One other thing, my engine light has been on forever, the codes lead to 02 and 0bd problems. I had the efie on with no hho as I was rebuilding. It was set on about 0.22. The other day the check engine light just went off. The minute I hooked HHO backup, it came on. I've been playing with the efie for a few days now and not getting any better, maybe a hair here and there.

If you add too much voltage to the 02 sensor your ECM will thing the 02 sensor is bad and go into limp home mode. The check engine light will come on and the ECM will set your fuel mixture to all the way rich to prevent a lean burn condition. Too lean a mixture will cause high cylinder head temps and possibly burn your pistons. Ignore the after cat 02. Start with the front 02 and start adding voltage slowly. It is a very tedious process but the gains are worth it. The readings you are getting are normal. The lower the voltage the richer the air fuel mixture is. When you add too much voltage at one time the ECM adds more fuel and expects to see a substantial voltage drop. If you are adding too much voltage the ECM does not see what it expects and goes into limp home mode. If this happens just unhook your battery for a couple minutes. That will clear the codes. Drop the amount of voltage you are adding and start over. GO SLOW AND YOU WILL GET GAINS.

[bigapple]

So ideal reading is 0.45 volts for an 02 sensor right? Mine reads 0.13 on average. If I rev up the engine, it will go almost to 1.0 and drop back down. I replaced 1 (I have 2 on 2002 jeep 4.0L) but both still have the same reading. Why is it so low? Then engine is warm when testing. Any thoughts? Please help.


Ok, hold on, went and did another check. With my multimeter set on 20, on battery of course, reads 13.6v. On the 02 sensor, it fluctuates at 0.04 to 0.05, is it supposed to be 0.045 on the reading? I'm getting a little mixed up on this. Checking my efie to set it, it will go from 0.000 to 0.60, that is the furthest I've taken it. Someone please get me on the right path here, this is driving me freakin insane! One other thing, my engine light has been on forever, the codes lead to 02 and 0bd problems. I had the efie on with no hho as I was rebuilding. It was set on about 0.22. The other day the check engine light just went off. The minute I hooked HHO backup, it came on. I've been playing with the efie for a few days now and not getting any better, maybe a hair here and there.

Also, with the Check Engine light; unplug your battery for a couple minutes to reset your ECU and start fresh with a mixture. I had some issues with my generator when it was installed (left it on and the engine gulped some water). The knock sensors set off an engine code and there were probably others there. I did seafoam treatment to clean out what I messed up, and unplugged the battery to reset the computer. The light is off and I know I'm safe to go into the testing phase with different types of injections.

Might not be the fix-all but it's definitely worth a try. Unplug the battery and let it sit for a minute and then plug it back up. Might get rid of that light.

[richardb200373]

Thank you both, you are definitly right on those answers. Redneck, my jeep also has 4 sensors like you say, 2 in front and 2 after the cat. I assume the other 2 after the cat will not need to be messed with right? Actualy, on mine, the top sensors are right at the manifold, then there are two big tubes which I assume are cats; but, there appears to be another cat or something further down the exhaust line. I know quite a bit about vehicles but I am deffinitly not a mechanic.

I ran the vehicle a while ago about 60 miles. My reading did come up on the new 02 sensor, seemed normal, about 45ish fluctuating, ok, got that one down. The second one was only about 35, so I stoped and bought another new sensor and am going to replace it and hopefuly my little magic ferry will show up and turn off the engine light.

Thanks again for your help guys, I'm sure I'll be back for something.

[richardb200373]

Big apple, I had an explorer like yours before my jeep. Anyway, my jeep and your explorer are about the same engine, etc. other than straight 6, what kind of gains are you seeing? Thanks

[HiTechRedNeck73]

Thank you both, you are definitly right on those answers. Redneck, my jeep also has 4 sensors like you say, 2 in front and 2 after the cat. I assume the other 2 after the cat will not need to be messed with right? Actualy, on mine, the top sensors are right at the manifold, then there are two big tubes which I assume are cats; but, there appears to be another cat or something further down the exhaust line. I know quite a bit about vehicles but I am deffinitly not a mechanic.

I ran the vehicle a while ago about 60 miles. My reading did come up on the new 02 sensor, seemed normal, about 45ish fluctuating, ok, got that one down. The second one was only about 35, so I stoped and bought another new sensor and am going to replace it and hopefuly my little magic ferry will show up and turn off the engine light.

Thanks again for your help guys, I'm sure I'll be back for something.

have you done a key dance or OBD reader to see what your errors are?

the key dance is a chrysler thing, turn the key on (the key must turn all the way on, but not start the engine) then off (off must be off not accessory) twice, the on again and leave on (within 5 secs)... this will use the odometer display to give you the codes... write down all the "Pxxx" codes and either look them up or post them here and I can help you... you need to let the computer work for you not fight with it... if you post your codes here, don't forget to include year, make, model, & engine of your vehicle... if you want to look up your own codes, I suggest this site:

http://www.obd-codes.com/

you can gain direct access to codes by adding the code to the address above... for example, if I wanted to know about P0304 I would enter this address...

http://www.obd-codes.com/p0304

H2OPWR is right that most codes will cause a "limp mode" and you won't see any fuel savings... that is why it is so important to get them all gone and stay gone...

also, are you using EFIE on both of the upstream (manifold) o2 sensors... you must have one on each unless you have one that controls both at the same time... but you need to be able to adjust independently...

another question for you, did you try extenders 1st? it's my understanding from a few different sources that the extenders work on chrysler vehicles... but you have to double them up and get ones with a small hole so you can drill them out to customize for your vehicle... I'm just curious... heard that from more than just here and I'm trying to simplify my setup...

[bigapple]

Big apple, I had an explorer like yours before my jeep. Anyway, my jeep and your explorer are about the same engine, etc. other than straight 6, what kind of gains are you seeing? Thanks

You are right on that since both have a displacement of 4.0L. I never got my generator completely running without leaks because the gasket sealer I was using was actually affected by the electrolyte and caused it to spring leaks. But I know that once I get Neoprene rubber cement, I won't have to worry about leaks because it doesn't react with KOH or NaOH and it's super adhesive. I'll keep you posted when I get results with that. Right now I'm experimenting with water vapor injection and I'll stack that with my hydroxy generator once I get everything sturdy and up and running.

[JonDoh]

Thanks to all! You guys helped me out just by reading your posts! :)

[richardb200373]

Thanks to all for replys. Redneck, I saw one of your posts about getting the codes which I did yesterday, thanks, that helped. My engine light is out now thank God! I still did the key thing anyway and these are still coming up : P0031, P0051, P0136. If I remember, 136 is an 02 error, and I'm pretty sure the others are too. I coundn't find those too on that site you were talking about, but I think it is low voltage code on 02. A few others that came up a few days ago was P0152, P0175, and P0460, I think all 02 related also.
ANYWAY, here's what happened, I replaced 02 sensors a while back, got to thinking and looked at the box, they gave me the sensors for after the cat, got those replaced, still had the engine light on. I reset the ecu by unplugging the negative battery cable for an hour. Then I remembered someone saying to pull the fuse or relay under the hood for it also, well, did'nt find that one, but I did see a fuse that said 02, and guess what.....damn thing was blown! My luck. Oh well, played with the efie until the engine was choking, then brought it back to about 0.20, tried a few other settings, seemed that I had some change on about 0.30 but not sure, too many hills and mountains right here close to home, need to get out on flat interstate.
How much should I be moving the efie when testing?, 0.01, 0.05, ?
Thanks again guys, I'll keep you posted on my progress.
Richard

[HiTechRedNeck73]

ok, here is what I found in my Factory Service Manuals...

P0031 - o2 sensor 1/1 heater circuit low
P0051 - o2 sensor 2/1 heater circuit low
P0136 - o2 sensor 1/2 heater relay circuit open or shorted
P0152 - o2 sensor 2/1 shorted to voltage
P0175 - o2 sensor 2/1 fuel system rich
P0460 - fuel level unit, no change over miles

my opinion is such...

P0031 & P0051 are related, and I had a similar problem recently... there is a 5-volt regulated power supply in the PCM that supplies all the sensors a basic 5-volts to operate. my front sensors were throwing this code just as yours are... I thought there was something wrong with the front sensors... but after changing them, the code remained. after looking at the wiring schematics, I discovered a flaw in Chrysler's design... the 5-volt power tap used by the o2 sensor heaters goes to the rear sensors first and then to the front... this is important because the sensors heaters are electric resistance heaters... for if your resistance is too high in the rear it will supply too much voltage to the front and if resistance is not enough, then there will be a shortage of voltage up front... because electricity travels in the path of least resistance... well, after pulling the rears, I discovered that they were the wrong sensors for my year... after 2002, Chrysler vehicles have different front and rear sensors... they are not universal after 2002... so I caution you to check your rear sensors...

P0136 & P0152 you found with the blown fuse... don't know what happened there, but may be related to your adjustments

P0175 is a no brainer

P0460 is very interesting... it took me forever to find it... Chrysler PCMs store MPG in the computer for use of overhead readouts or the use of a DRBIII (Chrysler's proprietary ODB reader)... the reason it's so interesting is that usually only MAF-based cars have MPG in the computer... MAF-based systems can calc MPG on the fly... Chrysler doesn't use any MAF systems, they are MAP-based engines (usually no MPG being calc)... it's what allowed them to get the EPA to allow them to build cars without EGR valves, of which they have not had since 2002. they showed the EPA that their engines had less emissions without and they were given special permission to remove them... it was a very cool thing... anyway, sorry to get off topic... so the computer actually monitors the level in the tank as part of the mileage... I'm going to check into this further... it's very interesting... basically, it looks for a certain amount of change in the tank after so many miles... I don't know what those variables are, but I will find them and post the info... so if you took a Chrysler vehicle and got it to 100% hydrogen, or even just beyond what the computer expects, then it will throw this code... so much for having hho and no codes...

I will keep you posted on any more I find...

[HiTechRedNeck73]

P0460...

>0.1volt change in ________ measure of time in idle

>0.1765volt change in ________ miles while driving

looks as if the voltage from the tank sender is lower on full and raises as the tank empties... since the voltages listed didn't have a + or - sign on them in the manual...

I did find this info in the FSM after my last post... there is a proceedure to test the reading, but it references a manual I don't have in front of me... I'm still looking... but since these are settings in the PCM based on engine, it means they can be programmed to a different setting...

really great stuff... this confirms something I've been fighting my local mechanic about... thanks for bring it up...

[hg2]

Hitechredneck you said dodge hasn't had egr valves since 2002.My dodge truck is post 2002 and I had to replace my egr valve last year.Where did you read this,just curious?

[richardb200373]

Redneck, thank you for looking up all that information, very generous of you using time and skills on this. I only reset my computer for a minute after the engine light went out, so maybe if I take the negative off for a while, it will take away the 31 and 51. In all this same time is when I replaced the 02 sensors also (last night). As for 136 and the other ones, I did pierce the wire with my multimeter to test, which I probably should'nt have done, don't know if this is hurting it or not or if that is what is giving off these signals.
As for the different 02 sensors, you are right. They call them universal, but there are 2 different types for front and rear. I guess the universal is for different cars. I think the part numbers are 15029 (front) and 15030 (after cat) for Bosch sensors from auto zone. That was also part of my mix up was the wrong ones were given to me.
Well, I'm getting closer, at least the engine light is off, now just need to fine tune. I stopped for coffee last night while test running (turned jeep off) and my vinegar in the bubbler got sucked into my tank which has 1/2 cup Koh to one gallon distilled water, so that is all mixed up, going to have to drain again today. It was still producing but not quite as much. My cell is pushing more out than fluid going back in (dry cell). I have 2 tubes up top and only 1 on the bottom, I should probably switch them around. I think a longer hose to the bubbler will take care of my sucking back in problem. Sorry to get off subject.
Anyway, how much should I be adjusting my efie at a time, 0.01, 0.05?
Thanks again for your help and thank you for looking up those codes.

Oh, also forgot to add, my jeep has the mileage display on it - it does average, instant mpg, and distance to empty, I remember you said something about this and the MAP I think. It seems to be some what close. It's hard around here with the hills and mountains. I just need to get on the road for a day and do some testing.
Thanks again.

[HiTechRedNeck73]

Hitechredneck you said dodge hasn't had egr valves since 2002.My dodge truck is post 2002 and I had to replace my egr valve last year.Where did you read this,just curious?

I was under the impression that is was all chrysler vehicles... my 2004 Intrepid doesn't have one and my dad's 2006 Ram w/Hemi doesn't have one... I don't know what to say... it was an article posted on the EPA's website if memory serves... someone mentioned it on another site and I went looking for proof after I noticed that my own car didn't have one... I will find the article and post the link...

[hg2]

I was under the impression that is was all chrysler vehicles... my 2004 Intrepid doesn't have one and my dad's 2006 Ram w/Hemi doesn't have one... I don't know what to say... it was an article posted on the EPA's website if memory serves... someone mentioned it on another site and I went looking for proof after I noticed that my own car didn't have one... I will find the article and post the link...

I know because the first code my truck set was egr and it was located on the front of the head on the passenger side.The truck was under extended warrany and I remember the valve was less too buy than my $100 deductible,and took about 20 min. to replace.

[HiTechRedNeck73]

I know because the first code my truck set was egr and it was located on the front of the head on the passenger side.The truck was under extended warrany and I remember the valve was less too buy than my $100 deductible,and took about 20 min. to replace.

what year and engine... I don't recall any EGR valves on the front head area of the chrysler engines...

the purpose of an EGR valve is to dump unburned exhaust fumes back into the intake system to pass through the engine again... are you sure we are talking about the same thing...

usually they are in the rear or on the side... they will have a tube that comes off the exhaust or an exhaust port on the head and the other side will connect to the intake or plenum in some way... also strange that is was less than $100... usually those things are more than what they are worth...

I've not found the article yet, but I will, just have to remember the way I found it in the first place... it's been quite a few months and it's just not jumping out at me...

[hg2]

what year and engine... I don't recall any EGR valves on the front head area of the chrysler engines...

the purpose of an EGR valve is to dump unburned exhaust fumes back into the intake system to pass through the engine again... are you sure we are talking about the same thing...

usually they are in the rear or on the side... they will have a tube that comes off the exhaust or an exhaust port on the head and the other side will connect to the intake or plenum in some way... also strange that is was less than $100... usually those things are more than what they are worth...

I've not found the article yet, but I will, just have to remember the way I found it in the first place... it's been quite a few months and it's just not jumping out at me...

It did have an exaust tube coming up from the rear of the head leading to the front.The shop that read the code for me was one of my customers and he said they were about $300,and he also comented that sounded cheap when I told him how much it cost for one.I got at the dodge dealership.

[HiTechRedNeck73]

It did have an exaust tube coming up from the rear of the head leading to the front.The shop that read the code for me was one of my customers and he said they were about $300,and he also comented that sounded cheap when I told him how much it cost for one.I got at the dodge dealership.

wow, you got a great deal considering it came from the stealership...

[hg2]

wow, you got a great deal considering it came from the stealership...

I just called the dealership and the part number is 53032-509AM and they 're $80.56 now,I guess they went up like everything else.This was about 2 years ago when it went bad.

[retsofarik]

In reguards to the o2 sensor, is wrapping them to contain the heat, fool the computer into a rich enviornment & make the pulse width of the injectors narrow by some nano seconds?

[HiTechRedNeck73]

In reguards to the o2 sensor, is wrapping them to contain the heat, fool the computer into a rich enviornment & make the pulse width of the injectors narrow by some nano seconds?

my personal opinion is to never wrap an o2 sensor... others may have a different opinion... it may fool the computer for a short time, but if its a 4-wire o2 sensor, you could overheat the heating element or overheat the reference air inside the unit... that, IMO would reduce the life of the unit... I wouldn't do it on a 4-wire o2 sensor...

my experience has only been on 4-wire sensors, so I have no opinion about 1, 2 or 3-wire sensors and I have no experience on 5-wire, but they get reference air from an outside source... so I don't know if those fool the same way... I'd think not...

[hg2]

In reguards to the o2 sensor, is wrapping them to contain the heat, fool the computer into a rich enviornment & make the pulse width of the injectors narrow by some nano seconds?

The reason you wrap O2s is to keep them out of the exhaust flow.which is like using an O2 extender,but a bad way to do it.

[HHOinKY]

Might sound like a dumb question, but where do you hook your meter to on your 02 sensors? And can you have it hooked up and reading the meter while you're driving?

I guess you could hook the sensor to other wires and run the wires into your car and drive and read as you drive?


Mitch

P.S. This thread is helping me out alot. Keep it up. I'm sure others are benifiting from it greatly also.

[HiTechRedNeck73]

Might sound like a dumb question, but where do you hook your meter to on your 02 sensors? And can you have it hooked up and reading the meter while you're driving?

I guess you could hook the sensor to other wires and run the wires into your car and drive and read as you drive?


Mitch

P.S. This thread is helping me out alot. Keep it up. I'm sure others are benifiting from it greatly also.

the easiest and safest method is through the OBD port and using a computer you can log the data... that's what I do...

if you try it with a DMM, and have a 4-wire o2 sensor, the white wires are the heater element and depending on the make of car, one of the other wires is 5-volt from the ECU and the other is something less going to the ECU... the one that is usually less than 1-volt is the signal back to the ECU and that is the one you want to monitor...

I wouldn't suggest doing it with a DMM... it's going to be hard enough trying to figure a way to keep the wires attached and out of the way of the hot exhaust pipes, not to mention getting the meter in the car and being able to read and record numbers while you're driving, even if someone was helping...

most OBD to PC programs and devices have graphing and data logging that makes this a snap...

here is a how-to I did on another forum on the equipment I have...

http://www.dodgeintrepid.net/forums/t116796/

there are links to the software I use also...

if anyone wants to see how this stuff works, you are free to download the working demo of the software from their site and if you email me, I can send you a copy of one of my logs so you can play it back and see what you have the possibility of seeing from your own vehicle...

the log playback makes the software think it's actually connected to the car at the time of playback... the digital gauges work and all according to raw OBD data stored in the log...