Regarding the knock sensor, I have replaced it with both a cheap and a high quality knock sensor. I have made sure to torque it to the correct specification. I have replaced the pig tail. I have even replaced the engine computer. I thought it might be an actual engine issue, but it seems to come on after clearing the code without revving the engine.
Dont clear the codes.
That doesnt fix anything. That is just throwing the information you need out the window and trying to start from scratch everytime.
You need those codes and all of the data that you can get from those codes.
Those codes are the ecm telling you something.
Everytime you disconnect the battery or clear the code you are loosing the information you need to know and you are forcing the ecm to restart the same process it went through before you cleared the codes.
You want those codes and all of the feedback you can get from the ecm.
It is telling you something.
Everytime you disconnect it or reset it you are loosing what it is trying to tell you.
Because it has to restart and go through all of its procedures and programming and start from scratch.
And it will still end up being the same thing.
In my experiance when I went all nutty and rebuilt my TBI and put a new distributer in and cleaned my egr and a new temp sensor and tpi and a new tps and a whole bunch of other crap all in one day I had a hell of a time getting all of that to reset and work toghether.
All of the GM flowcharts are set up for individual component replacement.
There is no "replace everything" all at once flow chart.
I was basically trying to force my 1994 ecm to operate with all of the components brand new and out of range.
It was an absolute mess.
I solved a few of the problems by getting it hot at zero tdc with the dist wire disconnected.
I finnaly got the damn thing to run right by replaceing the shorted wires at my manifold collant temp sensor and the grounds on the back of the passenger side head.
And the battery cables.
The number one source of electrical ******** on a gmt400 is the battery cables