Knock Sensor Troubleshooting

[hmclaughlin67]

I have a 2005 Yukon XL with the 5.3. About a month to a month and a half ago, i sprayed my engine with degreaser and just a regular water hose to try to locate an oil leak. Naturally, I got a CEL for P0332. I assumed this would just be the typical switch the KS and harness and have just been waiting to have the money and time to get it done, but two days ago I cleared the code from my dashboard like I always do, and the code didn’t come on at all for over 100 miles, no pending either. I also noticed that my oil level had dropped enough to add another quart in, but it did overfill a little bit. About 5 minutes later, the CEL came back on for the knock sensors again. Is this just a coincidence? Or could I actually be adding too much oil every time and causing a real knock in my engine?

 

[OR VietVet]

The slight overfill of oil should not be any problem. A pic of the amount of overfill or a measurement of the overfill would help. If you were down to the 1 quart low mark or just a hair above it and added a full quart of oil, you should be ok. When you degrease and water down an engine, you take a chance of messing with harness/connector connections and sometimes a dry out will fix a CEL light or other malfunction problem. I would go to the KS harnesses and inspect the wiring and connections. Sometimes just unplugging the connections and then plugging back in is enough friction to clean out. Or unplug and use some spray electrical cleaner. Or get some OE sensors and harnesses and intake gaskets and replace them. They do go bad eventually and an 05 may just need new. It is not a very hard replacement. If you do it, get an OE oil pressure sensor and replace it at the same time.