Hey y'all. My son's IS threw a P0300 today under hard acceleration and CEL was flashing. So he pulled over and shut it down. After letting it sit for a few minutes, he restarted it and it ran fine. Just FYI, plugs were changed with OEMs a few months ago. This is the second time it has happened; the first time was coincidentally also under hard accel.

Any ideas? Cats clogged? It only does it under hard pedal.

Thanks in advance.
Josh

 

Hard to say with so little information. The most common suspects are fuel and air delivery .

Clean the MAF sensor with suitable product, check air filter and check for leaks. To establish fuel issues, you'll need some live data like fuel trim information. However, that data is ignored during WOT operation as that kicks the ECM into open loop fueling from a look up table. The key ingredient is STFT and LTFT will likely be off if the car is running lean from say a clogged fuel pickup or something like that.

Find an indi to do a ride along and look at ECM data. Also a local parts store may have a hint when reviewing Freeze Frame Data from the ECM.

 

Will do. Thanks...!