Hi Scotty love your videos. I have a 2007 Toyota Highlander Hybrid with 209,000 miles that I use for rideshare business here in Austin, TX. I have a check engine light that has been on for quite some time PO171. I went to auto zone they said the mass air flow sensor was bad, so I replaced it. 4 days later the yellow check engine light came back on so I took it to Napa they said bank 1 and bank 2 is too lean. Would you tell me how to fix this problem, thank you in advance.

often vacuum leaks do that, but so can a bad maf sensor. If you bought a chinese made copy maf and not toyota OEM, that could be doing both codes now as maf effects both sides

Hello the first maf sensor I bought was cheap one from auto zone lasted a week. Check engine light came back on. Then Toyota told me at service dept put in the oem maf sensor made by Denso they said that is original oem part so I did. It lasted 4 days before check engine light came back on.