Engine code P0332

[Alex Park]

2002 Chevy Silverado 2500 4x4 6.0l

 

A few weeks ago my check engine light came on. I had it checked out by a GM dealership. Code is P0332, Knock Sensor 2 Circuit Low Input (Bank 2). The dealership wants $875.00 to replace both sensors, harneses, etc..

 

I had my friend clear the code and I drove around (city driving) for 3 weeks, no engine light came on. I do not heer any knocking or oinging, the truck seems to run great, power is good.

 

I took the truck on the highway and after a few minutes the check engine light on and when I checked the code, it was the same p0332.

 

My question is why I only get the problem when driving on the highway.