After installed the MAF, I put the car on dyno. A/F goes 16:1 at the idle and 14.5 around 4000 rpm. It is way too lean to drive. I left the car at the grage. Anyone knows a Dyno tunnign shop near montreal, canada. Maximum 7 hours drving.

Is that a/f 14.5 at 4000 at part throttle cruise or full throttle. Do you have a scanner to check your fuel trims.

what maf on what injectors...whats your set-up fuel wise

it is full throttle~~I'll scan it tommorow
I have a Svt oem MAF and 42 lbs injectors,

That maf probably isnt calibrated to those injectors, i dont remember how big the SVT ones are for sure though, but i dont think they are 42lbs.

Yeah, your transfer function is going be jacked up and you are running dangerously lean.

The SVT comes stock with 27 lb injectors.

If i have a MAF only can handle 27lbs injectors, Shouldn't my car runs rich not lean?

It makes sense that it would but its obviously not.

I would venture a guess that the ECU is learning how to deal with the larger injectors during closed loop operations with the feedback from the O2 sensor, and might be applying some type of trim to the open loop tables as well. I'm not sure how much "learned" inputs are used in the open loop stuff.

Who knows... The good thing for you is that the SVT MAF has a well known transfer function and is pretty much plug-n-play when it comes to tuning. Super simple for them to plop in the transfer function and all your problems should disappear.