As per my last couple of posts I have a 99 V6 Mustang
with 295,196 on the odometer and after putting on a K&N 57 series CAI the car has become hard to start and when running its idling at around 750RPM and will occasionally spike to just over 1000 and go back to around 750. After about 25-30Kms after installing the new CAI the "check engine" light came on. I grabbed my code reader and the codes were P0174/P0171 lean bank error codes, I cleared them and disconnected the battery over night and that seems to have temporarily solve the issue. Earlier today the car started far easier but after a short run into town and back, and after the car had cooled down I tried to start the car it turned over really hard, like its still not getting enough fuel. The car came with a cutback exhaust already installed and had a BBK CAI previously before I swapped it for a new K&N 57 series. I have cleaned the MAF sensor (which looked perfectly fine) and have ordered a new PCV valve from my local Ford dealer and am having a new fuel filter installed this friday to hopefully solve the issue.
Have any other members had issues with these kinds of mods on older V6 Mustangs? If so how did you fix the problem. This is my wives car and I really want a reliable car for her to cruise in. It has been mentioned to me that I may require a chip or a tuner for the car to get it running normally again. I'm hoping there is a more affordable DIY solution. Can any other members lend me some advice on how to proceed?