2006 SILVERADO 4X4 W/5.3L (B) L33 ENGINE. IT KEEPS THROWING KNOCK CODES, MISFIRE CODES 3rd CYL SOMETIMES AND IT DOESN'T GIVE YOU ANY WARNING BUT YOU STEP ON IT AND THEN YOU PUT YOUR FOOT TO THE FLOOR AND AT SOME POINT IT STARTS TO FINALLY MOVE. IT FEELS LIKE IT'S IN LIMP MODE. BUT MY BROTHER WITH ALMOST 30 YRS OF BEING A MECHANIC HAS NO CODES WITH ANY TYPES OF OTHER CODES ASIDE FROM THE ABOVE ONES AND THE EVAP ONES TOO???

ANYBODY GOT AN IDEA? I WAS THINKING OF DISCONNECTING THE BATTERY FOR A COUPLE OF HOURS HOPING TO RESET THINGS

 

You can try resetting the PCM - disconnect the battery cables and clamp or jumper them together for at least 1/2 hour - this allows current flow which will discharge backup power in the module and clear the keep alive/adaptive memory - but don’t hope it’s going to solve the problem.

List the specific codes you are getting.

What has been done to it so far?

 

I'll have to let you now what happens. I have been getting the Knock sensor code both before and after the repair was done. As for the misfire not sure if it's a false reading yet or not. But I will see what gets fixed or not.

 

If the reset doesn’t fix it, Please post the specific codes. There’s at least 2 or 3 codes for a knock sensor and several different codes for the EVAP system - without knowing what specific codes are set, diagnosis is limited to troubleshooting each circuit individually which is time consuming and unnecessary.

What repair was done to it?