i was wodnering if it would be possible to pick up a used knock snesor say off a parts car and see any improvement. im reeeaaallll tight on cash so i try anything to save a few bucks
thanks

 

If it works fine then you'll see a difference.

 

or what you could do, as I learned from the FAQ list (page 7) is to bypass the knock sensor with a 470k resistor (read there how) and see if you notice any improvement. You can even drive around for a while like this, until you get a good price on the sensor.

 

yeah but i wouldn't do that... after reading about the knock sensor... i'd rather get used one just in case....

 

It depends on how much you have to pay for the used KS. They routinely sell on EBAY for $40-$50, however you can also get a new one on EBAY for $90 (http://cgi.ebay.com/ebaymotors/ws/eB...tem=2428967431). I bought mine from this same seller. If you can get a used one for $20 bucks or so go for it, otherwise you could end up in the same position a few miles down the road. MY wifes KS went bad after only 40,000 miles.

Why do you think you need a new KS? If you are not getting code 0304 from your ECU, then you don't hav a bad KS. A good KS will measure ~550 k-Ohm resistance between the left pin of the KS and ground. You can check the resistance without removing the KS by following the harness to the connector. The connector has two pins, only one of them hooks up to the KS, so try them both. The act of whacking on the KS with your wrench can (temporarily) start it working again, so checking the KS once you removed it may not give you the bad reading you suspect. Hint: the connector is not the green one closest to the KS (1995-1996 models – most likely 1994-2000), it is a few inches closer to the front of the car. A heat shielded wire leads into the bottom of it and there are two wires coming out the top, one clear and one black.

 

And what you could've read is that people would rather be able to still use their knock sensor to detect knock in the engine. If you put on a resistor you still don't get the power back that you would get with a new KS. Removing THE MOST IMPORTANT( maybe) thing in the engine is not very smart...

 

Please read the source again. A brand new KS puts out 470k resistance if it is OK, that means that it does not detect a knock. So if you put the resistor in, you mimic an OK signal from a KS, so your engine will perform under the optimal ignition time map, resulting in full performance. The only downside to this it that the resistor is unable to detect the knock, so if there truly is a knock, your engine can't protect itself from it.

Summary: The 470k resistor is an effective and cheap way to test if the KS was really the cause of the lost performance, (without taking the sensor out), but risky to leave in for the longterm since your engine is unable to listen to the knock.

 

Addendum: (taken from the 4th gen faqs)

At sample 246 I skipped from 3rd to 5th and then just toyed with the throttle for a mile or so. As you can see once again, during cruise and light throttle the ECU wants to run as much timing as possible. 40-45 degrees appears to be the maximum advance. During acceleration the advance will be anywhere from 20-40 degrees, depending on how much throttle you are giving it. Anything from about 30% throttle and up (before the WOT map) should give you somewhere around the low/mid-20 degrees of advance, but it may drop to 18 degrees momentarily. (this observation will be important later )

During all of this the engine should feel torquey and responsive just like it should.