I've had a check engine light on for about a year now and never worried about it much because the car runs great and i've had plenty of other things to worry about. So the other day i pull the codes and i've got a code 22 (knock sensor) and 35 (something about a purge valve?)

 

Background info: I have about 1k miles on my new head gaskets and the whole engine was pulled to change them. Wiring was messed with and unplugged and such. Car seems to run similar to before, maybe with a bit more pep.

 

What is this purge valve? I don't really care about ti as long as it won't effect engine performance.

 

I have read on here about the knock sensor wiring being really iffy, what can i do to help this? Can i check the sensor itself before replacing it for resistance? What about checking the output from the ECU? Is the computer retarding timing and doing other bad things because of this error code?

 

Thanks guys. Hope to get this taken care of so i can fix this low idle problem.

Don't worry about the purge code - won't affect how it runs in the least. You can get rid of it by replaceing the purge solenoid with a 33 Ohm, 5 watt resistor - that will get rid of the light.

 

The original Knock sensors were flawed and crack with age. There is an updated part from the dealer - it's $65 or so and has a white plug instead of the original grey. Takes about 10 minutes to replace that sensor. It's behind and slightly under the intake manifold on the driver's side rear of the engine block. I have never had a replacement knock sensor still pull a code. Even on my Turbo where the last 10" of the harness to it was melted on a failed engine block - I replaced the wire and it runs fine to this day without the sheilding even.

 

GD

Good to know, I will be taking care of that asap.

 

So, dumb question, where is this purge solenoid?

It is under the manifold on the passenger side. A 3/8" drive extension with a 12mm socket can reach it from behind the manifold. You just remove the long, black intake snorkel, and the idle air control hose and it comes out from behind the manifold. It's a blue, two pin connector. They always fail it seems and the dealer wants about $80 for a new one so the resistor is a nice $5 fix. I get one from the junk yard and if it's not good, cut the connector off, and solder in the resistor.

 

GD