Hi all!

Any info for my consistent error codes 2-3-1 in obd1 and p0171 in obd2 would help.
I have replaced all my turbo vacuum tubes and did the pcv system full system replacement about 8 months ago. Still doing a homemade smoke test to find leaks like the video by Rspi made. Still not able to find any leaks yet.


I did an oil change w new Mann filter about 5 months ago with liquid moly synth 5w-40. The oil lol seems very low and I droved 3000 miles since last oil replacement. I know I need to do another soon. What is the best oil you recommend?. It's always humid year round in central tx mostly 90 degrees F.
Smoke is coming from my dipstick again.

I also replaced all my engine mounts 3 bottom one and the 2 subframe upper mounts just yesterday day on thanksgiving morning . The mounts seem to help to drive feel a lot but these recent codes keep popping up?

My main question is how do I clear these codes? I am worried that I might have early signs of a head gasket leak? I do hear a strange metal high pitch whistling noise when I start engine. I used to have bad compression before I did pcv system replacement and all the major vacuum tubes. Car drives very good but these codes keep popping up.

Any advice is greatly appreciated