Or you could take your 7,000 mile old car with a massive drivability issue to a qualified Chevrolet Tech and get it fixed for free

 

A lot of people I've seen on here say the stage upgrades get rid of that idle thing. My 07 does the same thing sometimes.

 

if it was supercharged im sure a stage kit would fix it

 

LOL good point

 

check engine light went away... wierd

 

It goes away after 3 warm up cycles.

I got that P0171 after installing my Rebel CAI. It's a 3'' intake, so it takes a little while for the computer to relearn itself with basically no restriciton from the intake. Now it rarely comes on, only when I'm stuck in traffic at idle it might come on, but once every 3 weeks max.

Check your vaccum lines maybe, or like it was said, try cleaning the MAF (if you have an oiled filter it might be the problem). They sell MAF sensor cleaner, it's a spray (you can use brake line cleaner also I believe).


This might also be why your car idles weird, cause the MAF has trouble monitoring all the air entering the engine.

 

This isn't correct. The P0171 is the PCM learning that the MAF calibration is off because you changed the pipe diameter the MAF is housed in. All its learning is that the fuel trim is now in excess of 20%. The MAF isn't the problem, the calibration in the PCM is since you altered the percentage of air its now sampling.

 

im having the same kind of problem my cruise wont work, and when i drive at 40 and let off the gas the rpms drop from 2500 to 1000 then it keeps going up and down without accelerating.

 

its an 08, it has a warranty, take it in and get it fixed, take it in and dont **** around with it, if u screw something up and the dealership can prove that while u were fukin around trying to fix it,u made it worse they try to deny the warranty work.

You shouldnt have to fix these issues urself with a basically brand new car that has a full warranty.

 

exactly what I meant, sorry if I wasn't clear

but about the pipe diameter thing, check this out:
the GMPP intake is 3'' for the part where the MAF sensor is in (then necks down to 2.5 in the plastic part of the pipe). My Rebel is also a 3'' pipe, so i don't fully agree with what you say.
So in both cases, my MAF sensor is in a 3'' pipe.
The code comes on because there's too much air for the PCM's calibration. That can be fixed with a tune, or if you wait it relearns itself over time.

 

It won't relearn a calibration, what it learns is a fuel trim which is a correction to a calibration. When that correction exceeds +20% g/cyl it will set p0171, when it exceeds -20% it sets p0172.

The problem is the original calibration is very close to setting a 20% correction, GM has since corrected it in updated software available at dealers. Even being a millimeter off is enough to set it which is why it only comes on sometimes in your case.

 

yea i know i was just seeing if other people had the same problem and see what they did so i can have an argument if the dealer gives me ****.