Hey I had a ported MAF sensor that was throwing a code and made the car run leaner at WOT so I replaced it with a stock on now I get 30 miles less to every tank of gas. Not sure the ported maf would effect teh AFR at part throttle since the o2 sensors would pick up a lean condition and correct it. I was going to set teh PE table for the fuel table up to have it around 13:1 across the board by putting -1 strait down the table but if the ported MAF could be tuned just the same and got better milage then why nto put that back on there...?

 

Was the stock MAF new or used? Only advice i can give you is to hook up a scanner to see what fueling demands the computer is making.

 

It was used off of another 94 lt1 and 6-speed I have laying around, 73000 miles, I also have datamaster but I am not sure exactly what I should look for...?

 

what is wot

 

do you have adjustable fuel pressure regulator? You need to raise the fuel pressure to 41 to 48 psi. this will solve lean out at wot!

 

Wide open throttle - TB opened as far as it can go.

 

Look at the Lterms. if you find the value of 108 or 160 then thats a warning flag. 128 is ideally what you want but since you stated you noticed a decrease in gas mileage... my guess would be youll find those Lterms down right at 108. Good luck.