Rome and I changed the knock sensor on my car a few days ago (got the pinnacle nissan one) and the car ran absolutly amazing for 2 days. Last night it started being slow again, causing me to be almost dead even with a fawking 100% stock auto cavalier!!! Anyways...what could be causing this? Car runs perfectly for 2 days, then goes back to being slow. I scanned the ECU a few hours ago and i still have a KS code. I never reset my ECU after changing the KS though, so i just asked them to clear all the codes. Does anybody know what my problem could possibly be??

 

Well, those Cavaliers are FAST! I feel your pain. I got a check engine light...

 

you probably have to reset the ECU and let it learn the new knock sensor...if the codes still in the ECU, it takes 50 turns of the key to learn anything new, unless you reset the ECU first

-matt

 

Check the KS grounding point. Sand it down a bit.

 

Stupid question, but where is the KS grounding point? Is it the connectors?

 

Right here

 

Be careful with those bolts; they're easy to break.

 

As already suggested, clean off the grounding points, and reset the ECU.

 

Ok thanks, I'm goint to do it when my manifold cools down.

 

Seriously ? 50 turns? Where did the figure come from?

When I look with my consult cable it says things like "Knock sensor circuit - 2 starts ago"... you reckon it has to hit 50 before it clears

IIRC the ecu will only throw the error once it has happened twice or something.. it Stores the code then if it hits it again it throws the CEL

 

I remember a while ago someone saying if you fix something on your car that once threw a code, lets say an O2 sensor, and you dont reset the ECU, then it takes 50 turns of the key for the ECU to learn that the part is fixed

-matt

 

I don't know the exact cycle time for the ECU to clear a code it has stored, e.g. the knock sensor in yours case. What I do know, is that it takes a preset number of start/stop cycles before the ECU will clear the code.

Why not just clear the code since you've already replaced the sensor?

 

i changed out my knock sensor and never reset my ecu and went for a test drive and it was such a difference. power back and didnt hesitate anymore....but that was the FIRST time i started my car after i installed it...