My sc runs rich with a strong fuel smell, harsh vibrations, and it sounds noticeably louder than normal. I thought it was just a simple misfire so I replaced the spark plugs, ignition coils, distributor cap & rotor, 1 fuel filter, and the fuel pressure regulator. After that, I finally get a code 31.
I know code 31 has something to do with the MAF sensor so I replaced that with a new one but STILL that didn’t fix it. She runs better with it unplugged.
Could it be the ECU?? PCV valve?? I am out of ideas please help!

 

If your ECU hasn't been serviced, I would heavily consider this before you throw more parts at it. Hope you didn't throw away your original MAF sensor. I would contact Tanin and get your ECU serviced. There are other places you can contact to get the ECU serviced, but I don't know them off the top of my head.

 

The previous owner had the ecu rebuilt only 2 years ago. Could it be that its faulty again? Also, I already went through 2 MAF sensors and the car is still giving me problems

 

I'm starting to have issues with my rebuilt one... Tanin is suggesting new ECU... Since they haven't encountered my issue.. I would dig into a maintenance issue before you dig back into the ECU.

 

This is accurate as we have never observed a code 31 MAF related problem coupled with any ECU problems or issues, or present prior to an ECU rebuild.

You can certainly send it in for diagnosis and we can use our test vehicles to confirm or deny the same issue you are having. 9 times out of 10 when we do this our vehicles run fine with no codes present.