01 Suburban knock sensor code return after replacement
 

I recently got a P0327 knock sensor code on my 2001 Suburban 5.3L. So I removed the intake and replaced both the sensors and harness. I did not silicone the rear as many have said to do because the guy I was working with said there was no actual reason to, so bad on me. I put everything back together cleared the lights and drove about 40 miles back home. It sat for 2 days and then this morning when driving to the store the code returned. I used cheap parts from from an online dealer so I was skeptical when I did the install. Like most people I can't afford car repairs and full price anything so I jumped at a chance the get the parts at about 1/3 the price of the brick and mortar stores. I know the choice not to seal was a bad idea but could that really cause a return in 40 miles of driving? Is there anything else that could cause this code to return other than the sensors being just being a cheap POS?

Tested the harness with about 100000 ohms at each lead.

Reading over 10k ohms is probably OK but I'd have to verify that in the service manual. Knock sensors are sensitive to poor handling, meaning if the have been dropped or roughly handled they could have problems. I'd suggest rechecking all connections making sure everything is clean and seated.

Put OEM sensors in and put the silicone on, there IS a reason for it to help keep moisture out. If you're buddy had ever seen them completely corroded and rusted in like they do he wouldn't say that. GM issued a bulletin for it so why wouldn't you?


Couldn't even guess how many times this scenario happens and 99% of the time putting in OE sensors solves it.

I am fixing to try a 100K resistor in my rear knock sensor lead and see I can defeat the PCM. I have replaced my knock sensors twice and my Burb only has 100K miles on it. First replacement about 60K miles. Now I am sure there is a problem with the PCM