Hey guys, got a problem. For any of you who know Doc, I have his tune on my car which is quite a bit on the rich side. Lets just say I tend to leave a puff of black smoke behind me when I floor it. lol. Its been working great, until yesterday. I was cruising around town, when my CEL came on. I checked out the code on my Aeroforce and saw it was P0171, which surprisingly enough is a Lean code. It keeps coming on almost everytime I come to a stop. Anyone have any ideas of what could be the problem? For a little extra info, I recently installed a full vibrant exhaust w/header. I have a 2.5 and 60's also, but thats been on for quite a while. Any help would be much appreciated.

 

Could be the MAF sensor .. do you have an aftermarket intake?

 

could be a leak anywhere after the maf sensor. intake leak, even an exhaust leak before one of your o2 sensors

 

I agree. Since he just installed the exhaust it's a possibility that there is a leak before the 02.

 

Usually when you are blowing black smoke out the back, it is from Bad Knock. I find it hard to believe a tune is THAT rich.

Since you have the Interceptor scan it for knock when those puffs come up, just to be on the safe side. Lean could explain the knock too, if it is knock.

I'm not saying I got it figured out, just coming at it from the less obvious side.

 

Thanks for the feedback guys. Yes I do have an intake, Injen, but thats been on for almost 6 months.
I definately do have an exhaust leak, I had no idea that could cause a lean code though. I already have replacement gaskets on order, (i was stupid and did not get new ones when i put on the header) so hopefully that will solve that problem. If not I got a buddy who works at meineke so he said he would put it on the lift and see if he can figure out exactly where the leak is coming from.
Thanks alot for the help fellas.

 

hit your MAF with some brake cleaner. And double check all your connects related to your intake, throttle body, there are also some cases of a failed intake manifold gasket causing that code...