i have a 03 GT, just bought a MAC CAI and 87mm MAF. i installed them today and car is surging. 1st and 2nd gear seem cool, and at times 3rd; but when im reducing speed the car like surges and jumps. when i give it gas its fine, its only when i decelerate. check engine light came on, but i reset it, but it still surges. any ideas on what this could be and how to fix?

 

if the maf is not set up for the size injectors you are running that could cause it.

 

the MAF is set up for 19 lb injectors, so im lost

 

SO your maf is set to your injectors, have you retuned the car since you've added the larger maf? that may be the problem. They could have tuned your car for the other mods you've done and it's creating a conflict with the new part.

 

+1, Ive heard that the car can be pretty touchy when you mess with the MAF...im sure you need some sort of tune to work it out.

 

whats the best way to get a tune?

 

I would just put the stock MAF back on. Unless your making serious power, you won't need a bigger MAF.

 

go to your local shop and get a dyno tune, it gets pricey, but worth it

 

+1 on the stock maf