I recently replaced my knock sensor about 2,000 miles ago. I haven't checked the codes yet but it feels like it is gone again. I let someone use my car for 5 days and they filled it up with 87 grade gas. Could that have mest up the knock sensor? Also could it have to do with the 2 ground screws not being cleaned. Please let me know.

 

KS probably caught some pinging so the stored code is causing the ECU to retard the ignition advance. Reset your ECU, clean the grounds, and you should be fine.

 

no...the knock sensor doesn't get messed up when you use a low grade gas, it detects knock caused by the gas, if it detects knock, it retards timing. thats probalby what happened and your car feels sluggish. the knock sensor is doing its job if your car feels sluggish with 87 octane, especially in this hot weather.

 

What should I do? SHould I buy fuel injection cleaner and fill up with 93?

 

does having the two ground screws not cleaned defeat the full purpose of the knock sensor replacement? i just replaced mine bout 4oo miles ago, but didnt really feel a difference, and it made me slower in the 1/4 mile. wen we changed it, we didnt clean the grounds...

 

Umass021 - just wait till that tank of fuel is spent, and then make sure you get the premium grade fuel next time. Check for codes - its quick and easy to make sure the KS code isn't set. You are probably just feeling that the car is slower because of the higher summer air temps and the fact that you are running the A/C.

MaximaSpd85 - If the KS code has not reposted, then your grounds were ok. It only takes a few mins to clean the grounds - so it wouldn't hurt to do that just to make sure your ECU is getting a good signal from the KS. Check for codes - make sure the KS code has not reposted. The heat/A/C comment in the previous paragraph applies to you as well.

 

Well this is with the a/c off plus I have driver the car on warmer days then this and it felt more alive. It feels slower under 3,000 rpm.

 

ok, thanks, just makin sure, no codes, but my track times still got worse after changing the ks and a o2 sensor