Hi Scotty I have a 2007 mercury Montego with 79000 miles on it I’m getting a p0171 code by itself I replaced the intake manifold gaskets the Maf sensor the Pcv valve and I deleted the code and drove 240 miles the light came back on lastnight and I scanned it again and the p0171 came back on I looked at freeze frame and it happened at 0 miles an hour my short fuel trim is 0.8 and my long fuel trim is 24.4 this code is bothering me I want it off and my car to run normal again it doesn’t idle rough no trouble starting. Any ideas what it could be or what I should do next I did smoke it and I didn’t have a leak in the intake, manifold gasket. I change those cleaned everything the top of the heads where the gasket set I have no idea what it could be
What was the ECT (temperature) in the Freeze Frame when the P0171 code was set?
What were the RPMs and the MAF sensor g/s?
Also, have you checked for exhaust leaks from the bank 1 exhaust manifold to the bank 1 catalytic converter?
Sorry man I didn’t see your reply I’m using my phone and sometimes doesn’t show up I apologize
Generally that means you have a vacuum like somewhere, so perhaps inject some smoke into the intake system and see where the smoke leaks are
I did that already I replaced the intake manifold gaskets where it was leaking from and now it threw the code again what else would you do next
measure your fuel pressure and test leakdown
My fuel pressure is 47.9 don’t have a leakdown tester
What is the range for the fuel pressure on my car I tried to look but I’m finding all different ranges and I want to be 100 percent sure
leakdown means the fuel pressure stays and doesn't drop. I don't have the specs for your car. You'll need to find a service manual. But usually for cars of that era it should be in the range of 50-60 psi.
I think I figured it out what the problem was I cleared the engine code. I drove 100 miles I scan the car no engine light on but pending code still shows does that mean the ECU has to relearn the part that I fixed or does it mean that I still have a problem? What should I do? Keep driving it longer and if the engine light doesn’t come on, then I’m good? That’s code just been driving me crazy I just want it to be fixed and over with.already
you already said it came back after you changed the gasket.
meaning of "pending" - https://innova-electronics.helpscoutdocs.com/article/89-pending-stored-permanent-and-oem-codes
Hey guys sorry for not replying back sooner with an update I finally fixed the problem my egr was bad I replaced it cleared the codes my fuel trims r below 10% plus or minus so I think I fixed it I let it idle for 30 mins before I replaced egr it would have came on and threw the code so as of now I drove 400 miles no lights on thank you everyone that helped me and took time to read and reply to me hope everybody had a good thanksgiving and hope you all have a merry Christmas