Bolonel

I have a few questions. To start I have a 2004 GT. Is it okay to just take off your mufflers and run a straight pipe? If so does it add any horsepower or increase gas mileage? Also my friend has the same vehicle and he removed the plastic casing around his air filter and left the filter exposed. He said he gets more power and better mileage. Can this harm the car in anyway? Like something getting in the filter? Thanks a lot.

Derf00

your post won't get much if any responses here. YOu need to post in the Tech forum sub forum 4.6L