2G P0170 Error Code, CEL on

[DurangoGS-T]

hey. first off i want to say that yeah i have searched for the code but there is a lot to read and i need to go study for my final today at 4:30. what i picked up from reading though, is that an exhaust leak can throw that code (fuel trim malfunction), unless i read it wrong. something about air getting sucked in or lost can cause the o2 sensor to read funny.

i have the 'useless' autometer A/F gauge and its all up in the lean section, and the guy at mitsu told me that its because the engine is lean and the ECU tries to richen it up, but the ECU is past the desired limit for adding fuel so it throws the code. he said it could be a vacuum leak, a fuel pressure problem, an injector issue, any number of things. my main question pertains to what i read about the exhaust leak. i put a 14b on this past weekend but we broke one of the turbo to manifold bolts. i have ordered a new one, but since then i have been rollin with the stud and two bolts, plus some RTV. could this be the problem? would it fix the fuel trim problem (as well as help regardless) to have that bolt in ASAP? thanks guys. i'm off to study

steve

 

[ADrewzki]

If there is a very severe leak like that, you will lose power and your turbo won't spool as fast. It could be something as simple as a faulty O2 sensor though. I'm leaning towards the O2 sensor.

 

[Staytuned]

Thats your problem there for sure. The stock o2 is getting hit with fresh oxygen leaking in from the manifold and the computer can't get it back to stoich condition.

 

[DurangoGS-T]

thanks guys. i'll put the bolt in as soon as mitsu gets it in. another question though: while the A/F is on lean, is it still safe to drive it? the guy at mitsu said its possible it could burn a piston or something, but wouldn't my temp gauge be showing a change if it was getting really hot? thanks,

steve

 

[Staytuned]

Whats happening is your o2 is getting a fake lean condition because of the extra air getting in around the manifold ......so in effect your are way richer now because the computer is firing in extra fuel to richen up what is thought to be an extreme lean condition.

Of course this is only my guess as to what is causing your CEL based on what you have told me.