Hi there - I am looking for help for an ongoing issue I have had with my car. My timeline is like this->

Check engine light came on with lean bank 1 (P0171), lean bank 2 (P0172) and evap vent valve stuck closed (P2422).

Repairs: I had the ignition coil, spark plug and purge valve changed. This made the codes disappear for a while.

Symptoms: Car turns after fill up at gas station. Need to hold gas pedal down while turning on the car to have it turn on. This happens when I fill up my tank when it has a quarter of a tank or less in it.

Since the light came back on I have had it evaluated by multiple mechanics and could not isolate the issue. They have stated the air flow sensor is working, smoke test is good, purge valve is working, shut off valve 58/4 working, both o2 sensors working and camshaft magnet adjuster is working.

Since then I have have had the charcoal cannister cleaned - engine light came back. I cleaned the MAF sensor with CRC cleaner - engine light came back.

Air filters have been cleaned and changed along the way too.

The other day I changed my PCV valve and cleared the codes and yesterday I had an oil change and had the purge valve and hose next to it cleaned. Today codes appeared, but not the same as before. This time they are Rich Bank 1 (P0172) and Rich Bank 2 (P0175).

What is going on here? Why would it switch from lean bank to rich bank? Did the PCV valve solve the lean bank problem and uncover a rich bank problem? I have noticed since the oil change yesterday that I have a extremely rough idle when turning on the car after it being off for a period of time. This happened when I drove away from the mechanic and again today when I took my car out. To the point where I reversed out of my driveway and couldn't press the gas to leave. Had to give it 5-10 more seconds before I could go anywhere.

Please help.

George