HI,
My Name is Bob Lasko. I have a 2004 Monte SS with a 3.8. Last week I have be getting a hot soak fluctuation in my idle when restarting after about 30 minutes. Yesterday I scanned the car and found code p0171. Looking through Monte Carlo Form, found threads dealing with this code. Look for vacuum leaks and clean the MAF sensor.
While looking for vacuum leaks on the right band at the intake manifold, found that a rubber cap to block off vacuum at the booster hose had rotted off. Put a cap on it and now there is no fluctuation in the idle and now the code does not come back.
I just wanted to return some the information the I got from this form.
hope this might help some one.

Bob Lasko

 

Thanks Bob, always helpful information.