I have Pace Setter LT's and 3" off road y-pipe that dumps into 3" exhaust piping and out of Quad Borla Tips. NO muffler and NO cats.

It seems to be running quite rich. Why would that be, and can I fix that?

 

Leaks in the exhaust system before the O2 sensors can cause that problem.

 

Injuneer is right, i have the same problem as u. it is my my header flange not sealing right. anyway. do u hear any ticking from under the hood?

 

sometimes.

will be checking for any leaks. thnx

 

my friend told me somethin like this, not sure if its true or not. since theres increased air flow don't the O2 sensors read more air than fuel and tell the computer there isnt enough fuel (saying its running lean) so it sends more fuel to compensate for the increased amounts of air causing it to run rich?

-Chris

 

Even if it would, you should still be able to override that with a good computer programming.......not???

 

yes, but you're on stock programming, no?

 

Not.....

Leaks give you faulty excess air reading in the exhaust and produce exactly the result he outlined..... the PCM adds fuel you don't need.

The closed loop target A/F ratio is hard coded into the PCM. You can't change it. And it would be sort of pointless (or a$$-backwards) to try and change the programming to compensate for exhaust leaks, rather than correct the exhaust leaks. Using programming to cover up an engine's problems could hardly be categorized as "good programming".