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1997 Chevrolet Pickup Bad Idle and Vibrations

My 1/2 ton pickup is making abnormal sounds while running, idle and on the road. It has 197K, so it is rather worn. The sound is like a constant huh huh huh huh huh huh huh. It was a little chilly this morning, and I was able to see the fumes, not smoke, from the tail pipe. I can obviously see that it is not a constant thing…it puffs out. huh huh huh huh huh huh huh huh huh huh

Any misfiring? The puffing noise you mention reminds me of an open spark plug hole.

Yes, I know you said you didn’t see any smoke from the tailpipe.

Lets see what the others have to suggest.

Well, I just had a mechanic tell me today that the injectors are ruined and need replacing. Also, the O2 sensor is bad. Does this sound correct?

If the O2 sensor was ‘bad’, you would have had a SEL or CEL. If so, find out the code number and post it here please.

what fuel sys, do you have ? TBI,CMFI,MFI?

maico