98GTstang

Well ive got the motor in, runs good except for the P0171 and P0174 lean codes that will not go away. Cleared them several times. The motor idles weird, idles fine for a little bit, then bogs down likes it going to die. Nothing seems to help unless the car is fully warmed up, then its almost perfect. Its died on me 3 times coming off the highway, just in neutral and slowing down on a exit ramp. I've uploaded my stock tune and that seemed to help just a little.. still having problems.

The engine is out of an 03 GT with 47k miles. I had to put my old 98 GT headers, fuel injectors, fuel rails and complete throttle body on it.

What is causing this problem! Someone please throw me some ideas. Ive checked tps, maf, egr, and pcv and dont hear any exhaust leaks.

mustangman03

what is the fuel pressure.

98GTstang

I dont know what the fuel pressure is. I have checked with a scanner and it is running a bit lean, didnt think it was enough to trip the check engine light and cause an idle problem.

I'll check the fuel pressure and see where that takes me.

mustangman03

do you have the screen before the MAF