When I bought my GT, the original owner put a BBK CAI on it. I do not know if he changed the MAF. Is there anyway to check to see what size it is? What is the stock size?

 

How to measure it?
Take it out and use a ruler.
Measure the diameter of the inside of the maf and you've got a pretty close estimate
As far as stock maf size I'm not sure-
(I'm speed density or I'd know [:@])

 

i think stock size is 55mm if its aftermarket like c&l or somethin it hink it is casted on the side of the body

 

so if it measures around 55mm in diameter then it is stock?

 

Corresct, im preety sure on most MAF cold airs its stock meter.

 

Yeah, 55mm is stock unless it's a cobra. I just got a 75mm PMAS (was Pro-M) from jdsperformance.com for $159 shipped. Good stuff!!