2000 Suburban check engine light

[bobbysmith]

I have a 2000 Suburban with a 5.3. I had multiple codes so i did a tune up and cleared all the codes. Drove all day on the interstate ran like new stopped at a gas station and let idle for about 5 minutes and light came on. Scanned codes and knock sensor and catalyst system codes. Cleared them and drove home on interstate same thing happened no codes until I stopped at home and let idle. Any suggestions? Knock sensors were replaced about a year and a half ago with AC Delco sensors.

[SpartanAutoworx]

Sounds like the knock sensors have failed again.

 

What cat codes are popping up?

[bobbysmith]

I dont remember. I'm at work and the truck is at home. I will look at lunch today.

[anumber1]

When you replaces the knock sensors, did you replace the wiring harnesses too? If not, that may be the issue.

 

The sensors corrode, the wiring gets Krispy. After a couple of comebacks, I do the wiring with the sensors when I have the intake off.

[bobbysmith]

Yes I got the kit from GM with harness and both sensors.

[Long Box 2k]

My Heater Hose connecter at the firewall leaked and collected in the knock sensor cavity and took out the rear sensor. I also kept getting a right bank converter below threshold. Had to replace both. I went with a walker Y pipe. Been 6 months and 8,000 miles with no problem. The cat code always came on at idle.