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P0171 and running rough

J

Justinkrahn

New member
Hey guys, not sure if this is the right spot to be posting, its only my second post on here.

So lately I have been having some issues with my car, it really idles like crap. Drives fine until on the freeway and cruising at 2000 rpm, the rpms start bouncing, I speed up and that goes away.
Yesterday I got a P0171 code that popped up for about an hour of driving, the code came out of no where, and disapeared.

attachment.php


Here is the data from the P0171

One thing that I have noticed is that my cars idle gets a hell of a lot better if I throw it in neutral or in park. It also runs better with the AC on.
It almost sounds like my engine is tapping the frame. Could this be a motor mount gone bad? I really not sure whats going on over here.


Here is what I have done in the last seven months, most very recent.

MAF Sensor (threw code, replaced) 7mos.
LIM Gaskets 7 mos.
IAC (very dirty, replaced) 7mos.
New Plugs 1mo.
Wires 1mo.
Coil Packs 6mos.
Temp Sensor 2 weeks

Sorry for the lack of info here, most of the time I have no idea whats going on.


2000 GTP Supercharged, no mods. 199,000 miles on it.

Thanks in advance for any advice!
 

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Your fuel trims are maxxed out at +16.4 and thats where the P0171 code comes from, you have a pretty bad vacuum leak somewhere.

If you can do a smoke test on the vacuum lines/intake to see where a leak is. And check all vacuum hoses for cracks and so on.
 
Awesome! Thanks for the suggestions. I don't have a smoke tester, is there an alternate way of doing this with like a cigarette or something? Also, I took a can of carb cleaner and sprayed it around all the hoses and the intake, no change in idle.

I did have my brother do the gaskets for me, when I had them done, do you think that he could have done them wrong or is this possibly a head gasket issue? I'm not loosing any coolant and there is no oil the water.

The code is gone and has not come back, but the car still has a rough idle and shakes pretty bad at start up for about 5-10 seconds.


Thanks again!
 
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