Low end bog problem
 

Help anyone. I have '03 GT with an auto. trans. stock 3.27 gear, K&N cold air intake, Predator tuner, and 2 chamber 40 series mufflers. My problem is now since I've swithed to 9'' wheels with 275/40's, the motor seems to have a noticable flat spot from idle to about 3000RPM's. It hooks now so there is very little wheel spin to get the RPM's up of idle. I've increased timing thru programmer at 2K-4K and it got worse. When I first start the car, from a cold start, and rev the engine it would hesitate before revving up. Changing the WOT fuel calibration to a little richer setting it cured the cold hesitation but still has a flat spot off idle. I'm planning a 4.10 gear swap in the future but untill then will a 70MM throttle body and pluenum change help any? No problems from 3000RPM's and up, pulls strong from there. If anyone has had similar problems and has found a cure please let me know. Thanks Mike:wallbash:

I used to have an auto, and had a problem like you, its just the converter, the stock converter is set at 1500, this happens with all stock autos, also make sure your traction control is off, this problem you are talking about is normal

i have a 01 GT 5 speed and it used to bog and hesitate when i was between 2000 and 3000 RPM but after that it would run smooth. it turns out that one of my coil packs was not working properly so i replaced it and i havent had any problems since

also try to run some injection cleaner

how much for the vemon system?