How is the ecu effected with add Hho and no cat's on truck??

[Jeepjones85]

After reading this http://www.hhoforums.com/showthread.php?t=2465&highlight=mixture what happens when you take your cats off
like I did, Will this help out more or make it worse? Iv got an 03 gmc fullsize truck 4.8 v8

[mytoyotasucks]

After reading this http://www.hhoforums.com/showthread.php?t=2465&highlight=mixture what happens when you take your cats off
like I did, Will this help out more or make it worse? Iv got an 03 gmc fullsize truck 4.8 v8

id be more worried of what the computer thinks with cats off, might through SES light.

[Jeepjones85]

well it did make the check engine light come on but I was gettin about 13 mpg and when they took the cats off I started getting 15.5mpg go figure , im running test right now on the hho setup I have to see what kind of mileage improvement I get

[Roland Jacques]

well it did make the check engine light come on but I was gettin about 13 mpg and when they took the cats off I started getting 15.5mpg go figure , im running test right now on the hho setup I have to see what kind of mileage improvement I get

What are you doing with the 02 sensors? pre and post

[Jeepjones85]

I didnt do anything to the o2 sensor there still pluged in and mounted in factory location, It did throw a o2 code and the check engine light stays on.
But I dont see how I get better gas mileage now, with them off the truck??
I took the old cats and held them up and you can still see the honey comb stuff inside and they weren't clogged up or anything... But Im still planing on getting some high flow cat's to put back on my truck, so the check engine light will go off...

[Painless]

I didnt do anything to the o2 sensor there still pluged in and mounted in factory location, It did throw a o2 code and the check engine light stays on.
But I dont see how I get better gas mileage now, with them off the truck??
I took the old cats and held them up and you can still see the honey comb stuff inside and they weren't clogged up or anything... But Im still planing on getting some high flow cat's to put back on my truck, so the check engine light will go off...
When the tuners remove their cats, they install an O2 simulator circuit in place of the post cat O2's.