muffler noises

[humbug]

i installed a hho generator in a nissan exterra and after 2 weeks of driving i heard a couple of popping noises coming from my exhaust, i was wondering if anybody knows what this could be. the car drives fine and i only have heard it couple of times while i was in a drive through

[jimbo40]

I thought it was my imagination but I have heard a pop twice now also.

[HomeGrown]

The popping noise is typically the sound of unburned gas in the exhaust.

[Smith03Jetta]

Popping out of the exhaust is always caused by an overly rich fuel mixture unless you have a damaged exhaust valve or your timing is severely off.

The HHO Generator is undoubtedly creating HHO. The Oxygen sensor is sensing the extra oxygen in the exhaust so it is assuming that you are at lower altitude or the equivalent. It is pushing more gasoline into the cylinders causing an elevated fuel level. This rich fuel mixture will cause you to lose power and it will reduce your fuel economy. In order to correct this you have to fool your ECU into thinking that you have a NORMAL oxygen level. This can be done with a number of different methods including but not limited to O2 Sensor extenders, EFIE, MAF signal enhancers or reprogramming your fuel map in your car's computer.

Considering that you are driving a Nissan, there are probably lots of aftermarket fuel management systems available. That's the way I would go if I were you.

There is one computer setting that you can change that will eliminate this popping but it will not correct the overall Rich Fuel problem. The Adaptation channel that controls the Deceleration fuel level will reduce or add fuel on deceleration. That will stop backfiring out the exhaust but it will do nothing to fix your overall rich fuel mixture on acceleration or normal driving. Those can be adjusted separately. I just didn't want you to make the mistake of correcting that particular setting and think you had fixed the larger problem.

If you don't have a clue what I'm talking about I suggest that you leave this site and spend some time reading performance forums for Nissan tuners. Learn about fuel management, software mods, etc.

[Phantom240]

Also check for exhaust leaks. Fuel can't combust without oxygen, and if you're burning it in the cylinder, it shouldn't ignite in the exhaust. My car backfires like hell when I engine brake, because I need to change one of my gaskets.

[Omega]

Also check for exhaust leaks. Fuel can't combust without oxygen, and if you're burning it in the cylinder, it shouldn't ignite in the exhaust. My car backfires like hell when I engine brake, because I need to change one of my gaskets.

Could be more oxygen out the tailpipe from the HHO than anticipated by the computer mapping, allowing it to pop.

[Phantom240]

Could be more oxygen out the tailpipe from the HHO than anticipated by the computer mapping, allowing it to pop.

Maybe he should just do a tuneup to make sure he's getting good combustion.

[Jaxom]

If it wasn't backfiring before the generator, and is with it installed, then a tune-up is not likely to fix the problem. Run the truck for a few days with the generator turned off to verify that it's the source of the problem.

You almost certainly have an overly rich condition being caused by a false lean reading from the O2 sensors, just as Smith was saying. There are band-aid fixes for this, but to do it right you'll have to change the EFI programming (which is beyond what most people can/will do.)

[HYDROTEKPRO]

If it wasn't backfiring before the generator, and is with it installed, then a tune-up is not likely to fix the problem. Run the truck for a few days with the generator turned off to verify that it's the source of the problem.

You almost certainly have an overly rich condition being caused by a false lean reading from the O2 sensors, just as Smith was saying. There are band-aid fixes for this, but to do it right you'll have to change the EFI programming (which is beyond what most people can/will do.)

So what do you recommend as the right way to change the EFI programming?

[Jaxom]

Take the vehicle to a reputable performance shop that offers EFI tuning.

Tuning EFI vehicles can get pretty complex. I've dabbled with it on my own vehicles but I won't do it for customers because it's just too easy to mess up an important setting and fry an engine. The hardware/software needed to interface with the car's computer has come down in cost, but it's still too pricey for the average Joe. A good OBDII tuning package can easily run into the hundreds or even thousands of dollars, and there's a steep learning curve associated with EFI tuning.

[Smith03Jetta]

Yes, what he said...

[Boltazar]

Popping from the tail pipe is a too rich gas mixture, this can cause the cat converter to over heat and burn out or start your car on fire.