I recently purchased a chevy HHR and I've been doing matinence chasing around codes from a code reader.
I recently notices that upon a cold start or lower tempatures the engine code for the knock sensor doesn't appear and only reappears after the engine has reached a certain tempature. Does anyone have any advice on what could be causing this issue? I have inspected the sensors wiring and the pig tail that goes into the sensor and was almost positive it was the pig tail connection, that was until I notices the code dissappear at lower tempatures. Please give me any advice yall have and thank you. I can get photos of anything yall think would be relevant.

Edit: it is an 07 chevy HHR with a 2.2L ecotec and the code I've been receiving is P0327 "knock sensor 1 circuit low input" I also had P0302 cylinder 2 mis but that code went away after I patched the cloth hose on the intake.

 

Welcome
Confirm what model and engine you have.
As far as dealing with engine codes, you need to post the actual code numbers you are getting. Descriptions of codes can be misleading or even wrong. You can get different or incorrect descriptions depending on what brand scanner or code reader you use. They aren’t all programmed the same.

 

I have edited the post to include the engine and codes I have and had, Thank you

 

Welcome to the site , I suggest you remove the valve cover and inspect the timing chain especially the front guide, if it’s damaged, the engine will knock. The knock sensor might need a cleaning and some dielectric grease. They don’t fail to often.

 

Thank you for all your help this solved those problems now I just have to figure out my new set of problems with the emissions system and my 02 sensors not working both the monitor 02 and monitor heated 02 have failed

 

Check the connections for corrosion or loose pins

 

What codes are you getting for the O2 sensors?