Quick Question!!

[Twitch]

I recently put Pacesetter headers on my 2000 GTP and my mpg has gone down from 20 to 17. I was getting 20 with just a CAI and after I put the headers on, my mpg droped and doẹsnt run at her best.

I put in new autolight 104s with the header install and run 91 octane.

Do I need to get a tune or is something else the problem?

[SJAndrew]

is your foot into it more trying to 'feel' or 'hear' the difference?

[Rico]

Make sure those Pacesetters aren't leaking 'cause that may be skewing AFR.

[Fivefingerdeathpunch]

Too cold of spark plugs, if dont have a smaller pulley.

[dsmuts]

I'd say header leak. It'll throw your afr way off and could dump to much fuel into the motor and you'll get crappy gas mileage.

[Sven the Sexman]

What about header choice? 1.75" primaries are a little much for a relatively stock car.