Another P0300

intergalactron said:

I have a 2020 Tahoe LT, 5.3 Flexfuel, 110,000 miles. It has a stored P0300 code. This code was set during a hard acceleration event (merging on an on ramp). Engine backfired, lost power, engine light came on and was flashing. I let off the gas and everything returned to normal. Engine light turned off within a few seconds. This has happened 3 or 4 times. All similar circumstances, but only the one time I noticed the engine light coming on/flashing.

Other possibly related symptoms: Occasional rough idle. Occasional poor shift quality. Occasional 'surging' (throttle held steady, engine rpm varying).

I'm at the beginning of trying to get this ironed out. Where do you suppose I ought to start looking?

Click to expand...

intergalactron said:

I did check my MAF sensor, didn’t see any dust or buildup on it. I hit it with a little canned air just to be sure it was clean, put it back, still runs the same.

Click to expand...

NardDog said:

Try unplugging it and see it runs better

Click to expand...

intergalactron said:

So its cold and snowy where I live so I've kinda back-burnered this. But I was thinking... My driver's side motor mount is shot. Could a little bit of clunking of that motor mount trip the knock sensor, causing some of this surging?

Click to expand...