BAttitude7689

I have a 98 Mustang GT and i just pulled these codes from my diablo tuner and just wondering what everyone thinks the possible solutions could be. P0171 & P0174. I also am running LT heads with no cats. Any ideas or advice from past experiences let me know please

jgorm

Talk to your tuner and have him dial the tune in better. It only pops codes if its over 25% out of calibration. If you have had the tune for a while with no issues, then i would suspect a vacuum or exhaust leak.

fisher2985

check your mass air flow sensor and also check to see if u have a vacuum leak.

BAttitude7689

I got the MAF sensor cleaned and my mechanic check for any vacuum leaks or exhaust leaks and still nothing....he stated since its a 98' I should change my plugs and wires and coil packs since there all stock original parts. also the car idles really low and sounds like it might stall when we had it up on the lift there was a a lot of shaking coming from the motor that wasn't normal..he thinks maybe one or more cylinders are misfiring. I'm not sure what to think? any thoughts?

MeanRedStang

I got a 98 GT with the exact problem P0171 P0174 P0136 P0141. O2's lean on Bank 1 & sensor 2

Full Magnaflow Exhaust without cats.

I also want to know if this is a result of having no Cats or is it a possible bad MAF or O2's?

98gtfun

i had the same problems, my misfiring was plug wire ends were folded in, not getting enough contact, i also had p0174 witch in my case was the exhaust system that was put on wasnt tightened good enough, it wore out the flance and was leaking, i had a new flange made a week ago and welded it on... code hasnt came back yet