PO300 Code on 97 Chevy

[scott_williams2]

97 Chevy 1500 5.7 vortec 250k miles. The other day I started it and it has a rough idle and backfire at idle or low rpm drives pretty good but not 100% recently changed plugs and wires and fuel filter 2 new batteries new crank sensor. Started shooting single po300 code that said random/ multiple misfire. Very generic code I know right. any suggestions?

 

[scott_williams2]

I’ll add that it sne

97 Chevy 1500 5.7 vortec 250k miles. The other day I started it and it has a rough idle and backfire at idle or low rpm drives pretty good but not 100% recently changed plugs and wires and fuel filter 2 new batteries new crank sensor. Started shooting single po300 code that said random/ multiple misfire. Very generic code I know right. any suggestions?

I’ll add that it smells like it’s burning rich more than usual

 

[RawbDidIt]

Did it happen immediately after changing plugs and wires? If so I'd say to double check the firing order and make sure th wires are routed to the correct plugs. If that doesn't fix it pull love data from a scanner and pull your plugs to see which cylinders are causing the issue.

You also mention a new crank sensor, was it running fine on the new crank sensor?

Why all the recent work? Are these parts that were properly diagnosed and replaced, or are you still chasing the original problem?

Sent from my SM-N976V using Tapatalk

 

[Schurkey]

Can the scan tool display REAL codes, or is it limited to "generic" codes?

In other words, can the code-reader be trusted? What does the cylinder-by-cylinder misfire record show?

 

[scott_williams2]

I changed the crank sensor cuz it shot a code before the issue it’s pretty much unrelated. I changed spark plugs and wires after the issue and it’s still doin it and it’s a generic code I can’t pull up misfire history

 

[1997]

Might help you out.
I solved my P0300 issue old school.

https://www.gmt400.com/threads/rough-idle-p0300-help.49025/

 

[scott_williams2]

Fixed it. Distributor and rotor solved it. I got lucky on that one