Hello, new here. Have a PO171 code on my wife's 2002 Camry with the 2AZ-FE 4 cylinder. Freeze frame data shows code was set during closed loop, 2400 rpm, coolant temp at 181, LT fuel trim at 44.5 and ST trim was 3.9 After a quick check, I found no pirate air or vacuum leaks. While observing live data, I noted fuel trims were still close to 45% and did not improve at higher rpm. I inspected the MAF and found quite a bit of gunk built up on the IAT sensor portion. I sprayed thoroughly with MAF cleaner until visible gunk was clear, allowed to dry, then reinstalled. I did not erase the code and I wound up having to drive the car with the wife and kids to visit family. On the way home, I noticed the MIL went out.
Plugged my scan tool back in and noticed, at idle, fuel trims dropped to closer to 25%, better but still not low enough and PO171 was still present. I switched to MAF live data and observed LB/m at idle (.49) and slowly increased engine rpm to 3000 while watching MAF data. Maximum LB/m reached was 1.3 LB/m. I googled LB/m to G/s and converted, the MAF is reading 3.7 G/s to 9.8 G/s.....

Sorry for the lengthy post but, can anyone tell me what the MAF should be reading? Is it possible the MAF is under reporting? Also, can someone give me the wiring pin out for the MAF/IAT so I can put my scope on the MAF 5v and signal ground to verify output voltages?

Thank you in advance