Knock sensor

[91Chuck]

I just purchased a 1991 K1500 4x.... the previous owner rebuilt the 5.7, and add a mild cam along with an eldelbrock intake. Small problem, the cel is on, and the code is for the Knock sensor. If I am correct, teh bigger than stock cam has set the code....is there a way around this. Long time sence I played with a Chevy. Anty and all help is apperciated!

[Jimmiee]

The knock sensor code sets when your computer hears a knock and it can't shut it up by retarding your timing. So a cam could indirectly cause a knock sensor code, as could any noise like a tappet, exhaust leak, fan belt, etc. Can you hear any engine pinging? Sometimes you can't hear the knock. Have you tried boosting your octane?

[91Chuck]

I,m running 93 octane. No noises at all.

[Jimmiee]

The next step is test the sensor. A scanner showing the signal from the sensor to the computer makes this an easy task. Watching the scanner, tap on the exhaust manifold with a wrench and see if the signal changes. This will test for a bad sensor.

[91Chuck]

Ok, I can get a scanner tommrow.