I bought a used Toyota corolla (From a private party) and within a few weeks, the check engine light came on so I did an OBD scanner and read the codes. At first only code P0171 (system too lean) popped up and I did research finding it could be a dirty MAF filter. I then checked the codes again the next day and now also have code P301 (cylinder misfire). What should I do here? Should I still bother cleaning the MAF sensor? I am not a car person at all but the tutorial on that seemed fairly easy, I'm not sure what else I could do on my own without professional help. Lastly, if anyone has experience with these codes how much would you think I'm looking at if I take it to a mechanic. 150K miles on the car and seems to run while aside from slide idle
If you don't feel comfortable doing the work yourself, take it to an independent mechanic for a proper diagnosis of the problem. Cleaning a MAF sensor for those of us who have been working on ICEs for 40 years is a relatively easy proposition. For the uninitiated, all the Youtube videos in the world won't help when you discover you can't put it back together correctly.
Check you plugs, wires and coils Cylinder 1 has a miss and causing the lean code.
Remember - "The road to Hell is paved with good intentions."
Went through that episode with the brake master cylinder on my 350. 600$ wasted
What cylinder is misfiring? An easy check is to clear the code swap the coil and see if the cylinder misfire changes to another cylinder. If it does replace all of them will quality oem parts. If the misfire stays on the same cylinder more investigation will be needed.
Here's a video from Scotty that talks about the P301 code.
https://www.youtube.com/watch?v=r9zNnAuPY2U
I will advice you to take the car to a professional engineer so as to avoid more serious issues to the car.
Aside from the ignition system like the plugs and coils, it could also be a compression issue that is causing the cylinder misfire or even a module problem.
