More strange '94 error code behavior

[David1966]

Driving this '94 LeSabre on the highway today, it started vibrating badly out of the blue, but then went back to fairly normal operation.

My brother and I test drove it tonight. We are still getting a persistent P0342 Error code reading, even though he replaced the cam sensor.

He drove while I monitored the Actron code scanner. After warming up for a while at highway speeds, it started to run rough and shake again. I hit the Read Codes command as this happened, and the ECM spit out 32 (!) Error Codes all at once. When the car started running fairly normally again, it only showed the P0342 code again.

Does this suggest a bad ECM? Or a bad PROM?

Thanks,
David A.

[David1966]

To answer my own question, my brother and I replaced the main computer module this morning.

All the unexplained trouble codes disappeared, the Service Engine Soon light went off, and the car runs perfectly. The original PROM seems to be fine.

David

[Jed Rule]

You guys are too good. You should have let everyone guess at it for a few days before you gave us the answer. Winner gets a cold one.