Have a 98 GT with the PI swap and bolts ons. Still running the stock headers. The car feels like it is getting robbed of power when at WOT, its like it runs out of breath at 4,000rpms. could the headers be the culprit? All maintenance is upto date.
I just answered your PM who did the tune? and like i said in the PM your MAF could be the culprit of your problems. I just see alot of issues with non Ford MAF's on modulars except SCT units. The Pro-M's and C&L's etc use sample tubes to trick the ecu for a certain injector size and thats just not needed with the newer cars since you can just change the injector size in the tune and keep the stock MAF. (unless pro-m changed) This tricking has caused alot of tuning issues and may be whats hurting you over 4000rpms.
The maf pro-m uses is stock, they just recalibrate it, it is calibrated for 24lb injectors. I had it tuned at Mustang Magic in deer park ny. Not sure what dyno it was.
How does pro-m calibrate it? The calibration on 96+ is done in the tune not the MAF itself thats why they have issues.
im not sure exactly how they do it but i had to send it back to them and they send it back to me recalibrated for 24lb injectors. I have not Retuned the car since the injector swap. Do i need to?
Yes, what they did is change the tube inside that tricks the car into working with different injectors. I would put the stock MAF back on then get it tuned to work with the 24's and see if that cures your issues.
