Did not want to start a new thread but my situation is a little different. I pulled this from another thread from the tuning section because its more approprate here. So here we go.
I keep getting a p0171 about 20 miles after I fill up the car w/ gas. Car has a Cobb Accessflash tune that was completed in Plano a little over a year ago for the former owner. The car is now in Virginia. I have had it fogged twice to look for vaccum leakes and cleaned the maf sensor. It seems to throw the code more now that the weather has turned colder it only did it once this summer. There is an idle issue has existed since I got the car back in June. Sometimes it will idle fine at about 600rpm other times its up/down. On a usual basis, It will rev up to 1500-2000 and down to 500 about 3 times and then settle at 600 when coming to a stop. At times it will die. Also seems to be consuming more fuel. Also motor was rebuilt @ cobb when it was tuned so all maintenance parts are fairly new. I do not have an AP to collect data. So what's my next move. Also, I do not want to chase my tail with switching out parts if it is a tune issue. But it should not be a tune issue, the ecu should be able to compensate for the environmental change, right?