[HabibiAnthony]

Hello everyone this is my first post, and just fyi this is my last resort to get an answer or guidance. Let me break it down, got a check engine light (P0171, system too lean bank 1) I also got a P112F, (my car has a rough idle when AC is off, and whenever I’m coming to a full stop at a red light, my RPMs dip just below 500 and acts as if its going to stall but immediately recovers after that. I checked for vacuum leaks, all is good, changed my MAF and fuel air filter, still no fix. Took it to a trusted German mechanic, ran the same test for vacuum leaks he found nothing. Hooked up the code reader, looks like all cylinders are misfiring, so I’ve ruled out injectors, because no way all injectors are bad. I’ve also replaced the fuel tank breather valve (on top of motor). I’m leaning towards maybe it’s my MAP or fuel filter… maybe even an O2 sensor. I have attached some pictures of codes that could maybe help you, also included a second reading from auto zone (pictures of the sheets of paper with their suggestion) Thank you in advance for any guidance!!

[HabibiAnthony]

Update: i replaced the MAP sensor, issue still persists! At this point im going crazy. Car runs fine while driving, but again a rough idle. I need a miracle

[LA430]

Random misfires, poor idle, P0171 and P112F could be a failing/failed PCV. I know the b58 has issues with the PCV I’m sure the 4 cylinder is similar.

I had all these symptoms when my PCV would fail on my Audi as well.

[HabibiAnthony]

Wouldn’t i hear a whistling noise coming from the engine if that was the case? Unless you’re referring to the hose only

[LA430]

They can fail in various ways. Just because there’s no whistle doesn’t mean it’s good. I don’t know how to diagnose the PCV, but it would be worth googling.

[HabibiAnthony]

Update: ended up being the hose and fuel pressure sensor connect to the fuel tank breather valve on top of motor