i have a 97 gsr, i had cel codes 7 only which was TPS. so i got a new throttle body with good sensors, and no more CEL. , but not done, i drive the car, its perfectly fine now after a few minutes when i go pass 4500rpm and up, CEL turns on, wtf and stays on, now i go home turn off then turn on. no cel code, so drove around same thing happened again, so i diagnosed by jumping the plug and i got code 23! KNOCK SENSOR! what does the knock sensor do and its purpose, how will a bad knock sensor affect my car? help!

 

The knock sensor detects detonation and retards the timing accordingly. Check to make sure that the wire is connected. The knock sensor is located beneath your intake manifold on the left side (driver) of the block.

I think a bad knock sensor will prevent VTEC operation on a stock P72 ECU.

 

vtec seems to engage fine. But prior to changing my throttle body, i didnt have a cel code for a knock sensor it all of sudden showed up after the throttle body was changed. Didnt touch anything beneath or behind the intake mani or any other sensors from the TPS and MAP plugs. any other thoughts?..ill try checking the wiring for the knock sensor.

 

If the knock sensor is not fixed and is prolonged for a long while unfixed say for someone else. (im gonna have it looked at and fixed tomorrow) what affects does it have to the motor overtime?.. btw the motor never had a cel code of a knock sensor before. just all of a sudden now. thanks

 

I wasn't sure about the VTEC operation, hence the "think".

It would be hard to accidentally bump the knock sensor. Does the car have a loss of power, especially at low-mid RPM?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by egg6vtak &raquo;</TD></TR><TR><TD CLASS="quote">If the knock sensor is not fixed and is prolonged for a long while unfixed say for someone else. (im gonna have it looked at and fixed tomorrow) what affects does it have to the motor overtime?.. btw the motor never had a cel code of a knock sensor before. just all of a sudden now. thanks</TD></TR></TABLE>

It should have little effect unless you are running low octane gas. Avoid WOT to prevent a situation conducive to knocking.

 

don't feel any loss of low-mid power..what is considered WOT?, cause i was taking the motor to near redline 7500-7800k today and yesterday evening. If that is considered WOT, where should the max to be shifting?

 

The real danger with a faulty knock sensor is lower RPM operation. WOT (wide open throttle) filles the cylinders fully and achieves the maximum compression ratio. If you are running premium fuel, knocking should not be an issue.

 

i see, yah i run only 91 octane fuel. good info, ill be getting it worked on asap though. Thanks!