i turbocharged my si about 1 month ago and everything was cool but a couple days ago i got my exhaust put on 2 1/2 in. piping all the way through no cat and im getting a code for running to rich. so know its trying to lean it out and its causing me to bogg. i also got a o2 heated sensor malf. these are the 2 cels i got p0135, and p0172 help!! what can i do to fix this?

 

The two codes are related.

Are both of your O2's still installed in the exhaust? If so, you need to pull the second one out and just plug the hole, or any of the other tricks that become necessary when you remove the cat.

Or, you could get a high flow cat and probably be back in business.

 

I don't think you have a heated 02, but I could be wrong, post your full car mode/year.

02 sensors measure A/F and they use pressure in their calculations, so that might be messing it up.

Chip your car, you'll be OBD1, and at that point you only use the forward 02 sensor location.

Feel free to ask any questions.

-PHiZ

 

i have a 00 civic si .
before i only had the cel for a heated o2 sensor malfunction. and a couple of days ago when i got the full piping exhaust no cat i plugged in the o2 sensor and then i got another code for running too rich, so now its trying to lean me out and causing me to run like shit.

 

well the no cat situation is gonna cause the 2nd o2 sensor to read way too much fuel because its not being changed in ur cat since u took it out, u can probably bypass the 2nd sensor by just removing it and plugging the hole.

 

are you sure your car is running rich, cause if it is you are shooting flames out of your tail pipe

no cat and a straight back exhaust will shoot fire when down shifting or shifting on high rpms

you should get that on tape

~boomer

 

i havent really took it to high rpms because im scared that since its sensing im running rich , its trying to lean it out. so im not running rich anymore because its trying to fix the problem and trying to lean it out.

 

The CEL code won't show a heated o2 fault if the car doesn't have a heated o2 The o2 sensor doesn't measure pressure at all, nor does it make any fuel adjustments based on pressure. That is the MAP sensor's job. He's in california, aka, not allowable. Then again, having no cat is a no-no as well...

 

yah i refuse to remove my cat, even if someone says "You will pass emissions" its there for a reason.

 

i have a buddy that does welding so if i need to pass smog i'll just put a cat on. does anyone have any advice on what to do, my car is running like shit because of this