This has been headache for me the past couple months, my car was tuned on crome and ran great for 2 months then this problem arose with the engine cutting out and would throw a code 20 and 36 then would run in open loop. I replaced my dizzy spark plugs\wires re-built the wiring harness ( to make sure nothing was shorting out or grounding) and it gotrid of the 36, still have the 20 because I don't even have a ELD.
Now another thing weird is sometimes the check engine light will not go out so I'm unable to check the codes to see wtf going wrong.
Could it possibly be the p28 ecu malfunctioning ????????