ben99sel

iTrader: (10)

I have cold air intake, y-pipe, cat back exhaust,.. and the air filter I cleaned not to long ago. When I really punch it, it seems to accelerate slower then it once did. I'm not sure when the fuel filter was changed last, but I did it quite a while ago. Could that cause this? Other than that the car runs very well, so I am not sure what it could be. On a related subject, is there any sort of gain out of a aftermarket fuel pressure regulator if you are not supercharged or on nitrous? Sorry for the noob questions... before you guys ask,...no knock sensor code either. Thanks

mzmtg

iTrader: (11)

How old are your spark plugs?

have you cleaned your throttle body lately?

Has it been really hot and humid?

ben99sel

iTrader: (10)

The spark plugs should still be good, and the throttle body was cleaned when I had my fuel injectors serviced. I live in Southern California, so it is alway pretty hot in the summer... I not sure it is from the heat though, it has definitely been hotter.

maximadoc

dude, reset your ecu and see if any codes pop up.
cause i had the same prob. and my knock sensor was bad. sy. were slow acceleration and bad gas milage.

XoPtOn

iTrader: (2)

u have a injen cai?

Jatan

iTrader: (3)

Make sure you're using premium fuel and put your stock intake back on and see if that helps. Does the car run smooth? Since you have a 99 Max, it could be that a coil pack is dying.

ben99sel

iTrader: (10)

Did you throw a code? cause that was literally the first thing I checked, does sound like my problem though. Why wouldn't it throw a code?

Terran

iTrader: (6)

Partially working KS might have that effect but not throw a code. Check out the faq on this as I'm really not familiar with it...just a guess.