Car bucks and MAF reads real high and car kinda bucks or stumble, we have ruled out bypass valve by trying another and disabling and blocking bypass with no change.

 

Is more info needed?

 

Try a new maf? Maybe a tune issue? Has the car been running fine for awhile before this?

 

I don't have any experience tuning maf on a boosted car... but generally bucking is lean, our bouncing back and forth while going too lean.

Had a wideband on it while its doing this?

I had a bad plug wire that made the car run like crap when it hit boost, but fine before hand. Not really bucking but it was cutting out.

 

Car was down awhile with Pcm issue did not do it before then. Different tune to but stock tune has been tried, Afr pegs rich cause maf gps goes
4xx. 2-3 diff maf have been tried but none new.

 

FYI When my maf wiring went bad and it wasnt reading, mine leaned way out. Just something to ponder.

 

My guess would be a bad FPR...

 

I'd guess it's in the tune then, obviously a stock tune won't work at all.

Go back a few tunes and start from there. I had an instance where I changed only the idle in a tune and it corrupted somehow and when my maf would hit a certain point the car would cut out bad. Went back a tune and uploaded and it was fine.

 

When I say stock tune not really stock but stock tables, Also car is fine WOT just under part throttle load. Another question is what kind of power will 48# inj handel in boosted form?