There has been a bunch of chatter around here lately about knock sensors and their quirks.

 

My 98 2.2 Impreza was bucking and surging and hesitating while driving but not enough to make the car undriveable and oddly not enough to throw a code. So I thought I'd try changing the knock sensor out.

 

Since I was working on a hunch I bought an El Cheapo ebay knock sensor (about $15 shipped to my door) and installed it to find a massive improvement in the car's performance and a huge grin on my face.

 

While I was doing the job I took my video camera along so I could share the experience and things that I learned:

 

Dang! I saw "Redneck" and thought there might be duct tape involved!

 

Yeah that one sensor can/does make quite a difference when it goes bad. It can cause trouble and not trip the CEL, or it can trip the CEL without ever causing trouble, but eventually it will cause problems because the ECU relies very heavily on input from the knock sensor.

 

You have the muffler squeak too! I loved that sound on my wagon. I had the same pitch on 3 different volume levels depending on throttle and engine speed.

Dang! I saw "Redneck" and thought there might be duct tape involved!

 

Yeah that one sensor can/does make quite a difference when it goes bad. It can cause trouble and not trip the CEL, or it can trip the CEL without ever causing trouble, but eventually it will cause problems because the ECU relies very heavily on input from the knock sensor.

 

You have the muffler squeak too! I loved that sound on my wagon. I had the same pitch on 3 different volume levels depending on throttle and engine speed.

 

Hahaha yep, I tell everyone it's my hillbilly turbocharger

 

I'm still shocked that the knock sensor could be behaving as badly as poorly as mine was but not light up the CEL...

Just curious, Fishy, who'd you get it from on fleabay? Figure for ten clams, I might give that a shot, see if it solves my hesitation issues. The ones I'm seeing on eBay are from $13 to $30. Still cheaper than local parts stores at $50 to $100...

I got my sensor for this guy:

http://myworld.ebay.ca/chandlermotorsportsinc/?_trksid=p4340.l2559

 

I have no affiliation or history of purchases with him/her I just rolled the dice and picked a cheap one to order.

 

The main thing is that every time I drive that car now I grin about how much better it works.

Nice, that's the one I was eyeing, too. Can't beat 13 darra shipped. Fekin love ebay. I just scored a pair of KYB-clone 4runner front struts for $28 shipped and Moog progressive rate rear coil springs for $34 shipped to go on the back of my GLW.