Lean codes thrown, unsure if tune can fix or CAI issue

I recently switched CAI's for my new hood, went from the Bullitt 85mm to the FRPP/Steeda 90mm CAI, but kept my same Bullitt elbow.

Car has been tuned by Lito and has been perfect. Now about 150 miles after the change, and 7-8 drive cycles, I get lean codes for both banks, P0171 and P0174. I cleared and returned few key cycles later.

I reached out to Lito and bought a tune revision from him and waiting for him to give a starter file, but I'm concerned my little 5mm difference at the filter head is enough to get these codes? Quick google search told me those codes throw at 1.29 Lambda, which is like 19:1 AFR! Is my engine really that lean? I can believe it if I had a stock tune, but Lito has it properly tuned for the 85mm CAI.

It is also off-road X, so lot of unrestricted air flow. Again, tuned for that. Only change was the 90mm CAI

Maf housing diameter changed, need to update maf transfer in the tune.

Juice said:

Maf housing diameter changed, need to update maf transfer in the tune.

Click to expand...

Exactly.

I once accidentally pulled my air filter off just slightly, so that there was a slight gap around where it attached to the 90 going to the TB (this was before the blower), and the car would barely run, and wouldn't idle on its own at all. Took me like 3 days to figure out what the problem was only to find out I just needed to fix the filter.

These cars are very sensitive to the CAI's.

If you increase the maf housing size from 85 to 90 mm you effectively change the cross section of the volume of air by about 12% That is a pretty big difference.

Just buy HP Tuners and do this stuff yourself. It’s super easy and kinda fun.

Tune cured it!