Air/Fuel Ratio Problems

0h3gt

New Member
May 16, 2009
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R.I.
I'm having air/fuel ration problems, i have a pypes x-pipe which seems to make my car run way to rich... I programmed it with my sct tuner to run leaner and the it was better at first but after a while it just starts to run like crap again (Iv'e done this many times) and its fouling out my plugs, can someone please give me some advice on how to correct this problem?? Is it my o2 sensors that are messing with the a/f mixture?
 
I doubt the exhaust is affecting the mixture unless it's done away with the O2 sensors or moved them so far away from the exhaust manifolds as to be useless.

Is the car throwing code(s)?

Does the car ever enter closed-loop fuel mode?

What are the fuel trims (long- and short-term)?

Can you explain what "run like crap" actually means? What is the car actually doing?

Does the SCT tuner allow you to see the fuel pressure and if so, what is it?
 
I'm not getting any codes, my car is idleing like it has a cylinder misfire but if i were to throw a new set of plugs in it would idle fine, 1g to 2g rpms its fine once its breaks about 2g's to 2500 it starts to run like its skipping or sputtering.....??
 
Could be a bad coil... Did you wash your engine recently? Is there any moisture in the plug wells? Can you answer any of trinity's questions (check engine light)?
 
Oh, didn't see your post up there about the codes.

What about your spark plug wells? Any moisture? Wash your engine bay?

What are your sort term and long term fuel trims doing?