stuttering stang

[cheaterpipe07]

ive got an 05 gt with a CAI, underdrive pulleys, CMC Deletes, and JMS 93 performance tune with 4:30 gears. The car has run great until a few days ago i noticed that at idle it has a miss in the exhaust note. At WOT from 3rd gear up at 4000+ rpm the car starts jerking and missing really bad. the ford dealer put it on the computer and said that that everything checks ok except he noticed that the right engine bank was running twice as rich as the left. my first thought is an O2 sensor but no codes are being thrown. Ive got less than 20000 miles on the car and i always baby it. please help me!

 

[86bluecobra]

I would also suspect the o2 sensor. either that or you have some sort of vacuum leak causing the engine to try to compensate with extra fuel.

 

[ski]

If one bank is running richer than the other, and the engine is missing, then everything is not ok.
Bad spark plug, plug coil, or plug wire???

 

[cheaterpipe07]

yeah i talked to the guys at JMS and they say the same thing, check the plugs. The dealership wants me to flash the computer back to stock so they can re check the O2 sensors. They said one was reading wierd yesterday and they want to see if it will do the same stuff tommarrow with the stock tune.

 

[nycstang37]

sorry i cant help, but good luck, glad to hear a dealer is even considering helping you out with the tune, its good to hear that some understand what we do with our cars.