P0171 help please

[jreask]

As the thread title says I have a CEL on with codes p0171 and p0440. I've read through numerous threads on here and need some advice.
2001 4Runner Sport 4WD V6 with 176K on the clock. So far I have cleaned and then replaced the MAF. The light came on about 243 miles later with both codes. I reset it with my cheap scan tool. It came on again in 9.8 miles with the same codes. I cannot detect any vacuum leaks. There was a hole in the air box that I epoxied closed. The PVC valve is working properly. New air filter. The PO had replaced the downstream sensor. He also replaced the evap pressure sensor at a cost of $619.00. He replaced the coolant temp sensor.
The dealer told him it was the cats. Cost -$3300!!!!! Wow.
My question is can the evap system help to cause a lean code (p0171)? Perhaps they are completely unrelated.
Here is the freeze frame data, the CEL comes on when idling.
Calc load 14.9
ECT. 194
Stft. 0.0
Ltft. 35.2
Eng RPM. 601
Veh speed. 0
Iat. 78.8

Would changing the canister possibly clear both codes?
Thanks in advance

 

[tyr0981]

My persistent P171 code was the POS K&N filter leaking oil onto the air flow meter (yes tiny little drops caused the error).

Pull the Airflow meter from the intake tube clean the little wires by spraying BRAKE CLEANER down there, or a solvent spray that doesn't leave a residue, there are cleaners out there meant specifically for cleaning AFM's, but brake clean worked fine for me for years. Don't brush or push on the electrodes, they're very fragile / sensitive.


**VERY IMPORTANT** ONLY CLEAN THE AFM AFTER THE ENGINE HAS BEEN OFF FOR AT LEAST AN HOUR! (they heat up while engine is on, and cooling them off too fast can damage them)