I have a 99 Forester, manual. CEL came on and started hesitating. Before I could get the code read, the light went off and normal operation for a few days. Then the light back on and hesitaion. This has repeated it self for the last couple of weeks. I finally got the code and it is the knock sensor.

Did a search on here and checked to make sure it wasn't loose and the connections are all clean.

I understand from reading here that when the sensor detects a knock the timming gets retarded to compensate and that is what causes the hesitation.

My question is: I know the part is not overly expensive (80-100) depending on where you get it but with xmas right around the corner would like to wait till Jan. What are the ramifications if any by waiting?

You mpg's will go down and loss of performance. You could run some higher octane in it to make sure you don't knock. If the CEL is on then that means that knock sensor is failing/ not working the way it should. Don't romp on the gas, take it easy and don't rev it too high

 

A online dealer such as subarugenuineparts.com will have a sensor for ~$50

Just got off the phone with the dealer and they want $181.00 for the part. Yikes...is it important to use oem for this part??

Just got off the phone with the dealer and they want $181.00 for the part. Yikes...is it important to use oem for this part??

Online discount dealers will sell you the OEM part for the price previously quoted by fnlyfnd.

Ok thanks, wonder why anybody would ever buy from the dealer with that much discrepancy..

Ok thanks, wonder why anybody would ever buy from the dealer with that much discrepancy..

 

I wonder why also. The biggest discrepancy I experienced was for a cam sensor. Dealer in Montreal wanted 160$ and I got it for around 20$ at 1stSubaruParts.

22060AA061 is the part number for a 1997-1999 Legacy EJ25 (i just bought one), they are 71.70 from subarugenuineparts.com. that's the DOHC engine, not sure if your forester is the same but the price will be nearly identical.

 

typical online prices should be %20 lower than MSRP, that's standard. seen that in multiple states all over the east coast of the US from Georgia to PA. your local dealer may give you these same discounted prices as the online Subaru parts dealers. you can ask if you have a good relationship with them or take in a printed pricing from the online guys and ask if they will match it. i've never been turned down. tell them you like the ease of not needing to drive but would rather have a relationship with the dealer. that's good for both parties and they should oblige. they give all the local shops that discounted rate anyway, so they really shouldn't care (at least in areas where there are a lot of Subaru's).

 

i prefer the online purchasing myself most of the time, saves time.

And 70.52 from 1stSubaruParts.

My dollar worth.

You could sub a Saab knock sensor (OEM Bosch) or sub a 520K resistor.

 

If you go the resistor route MAKE SURE YOU USE PREMIUM FUEL, as you have no knock protection.

I had the same trouble as you last summer with my 98 OBW. Light would go on then off, finally went on long enough to have the code pulled at Auto Zone. They told me it was the knock sensor. I bought one from them for $80 inc. tax out the door. Installed it myself with little difficulty. That fixed the problem.

 

Use the "search" feature on this forum to read past posts about installation, if you are a "do it your selfer".

When your CEL is illuminated and the ECU sees the Knock sensor fault it will keep the timeing retarded to prevent any preignition. No need to run premium fuel when the knock sensor is bad. Wait till Jan. if need be then replace it. People drive their Subarus somtimes for years with a bad knock sensor and no adverse effects.