My bad I guess that info would help.
I have a 94 r33 that came with an Rb25de. I installed a turbo and changed the ecu to a factory turbo ecu. I have a green label maf and it was working fine.
After two weeks of driving the car the car had hesitation issues and just felt off. Afr gauge wasn’t reading at all. Cleaned the maf and it ran the best it’s run. Afrs showed back up and the car was on point. Turned the car off and took it back out 20 minutes later and the afr gauge was out again. Maf wasn’t right and car felt sluggish