Last week, had a tune up done, knock sensors replaced, cover gasket valve replaced and air filter replaced . I’ve been haunted by the p0171(bank 1 lean) code for a while, but just recently also replaced the MAF sensor on my own and finally got rid of it! Disconnected the battery and drove around 130 miles...no pesky light.

Today I stopped for gas, drove it home and after starting it up again...CEL back on. I immediately double checked that the gas cap was on correctly and initially thought that MAYBE I hadn’t gotten rid of the lean code. After getting it scanned at autozone, I am now getting a lone p0446 code( evaporative emmision system vent control circuit) that I did not have previously. I will update tomorrow on whether it’s a gas cap fix. my question is: Is this all a coincidence? Or is there a possibility that a new fully functional MAF will point to other issues that were previously unseen?