1991 Grand Prix 3.1L Code 43

Hi, wondering if anyone can post the Alldata or similar step by step instructions for diagnosing the dreaded code 43 in a 1991 Grand Prix. I replaced the ignition module with one I had lying around and no changes. The car seems to run well, but mileage has dropped severely recently and code 43 appears 30 seconds or so after the car is started. I am planning on replacing the knock sensor, as that seems to be the 2nd most likely suspect. Thanks.

refresh my memory on OBD1, code 43 is.....

I'll check into it, but posting copyrighted repair procedures is aginst AF policy, so you may not get alldata per-say.

Jared, Check your Private Messages.

Code 43: Knock sensor signal was either above 3.5 volts or below 1.5 volts for at least 0.5 seconds.

What I'm about to say may be a repeat of what Tim PM'ed you about, so forgive me if it is. The 3.1's of all variants are known for piston slap issues which will trip knock sensor codes. It normally quiets down or goes away after the car has a run for a few seconds to a couple of minutes. This is considered normal unless it is a loud knock or doesn't quiet down.

Never thought of that Rich, good point!

Finally got a chance to look at the car again, found the wire going to the knock sensor had gotten caught on the cv axle and ripped in two, pulled the harness with the 2 ground wires and the connector going to the rack out and repaired the wires, everything seems great. thanks a ton for the help guys, i really appreciate it.

No Problem! Good Job! Thanks for the follow-up.

Cool, glad to hear you got it fixed. Thanks for the follow up, we like to hear the good news!