Knock Sensor Problem

[kitsubaru]

Hello..got a check engine light on. had car scanned. came up as knock sensor...and catalytic conv. both seem to have happened at the same time. soooo... first..haven't had it fixed yet...is this a serious problem for the engine since i've been driving it ? second ..does cleaning the contacts on the sensor rectify anything generally...or should i just replace it ? third......is the catalytic problem ? a result of the knock sensor being problematic ? if anyone can offer any advice ....thank you first post kit

[nipper]

i SWEAR i am going to start beating people with a nerf bat:banghead:

 

what year model engine trannny and milage are on the car. We cant do S**T without this information.

 

 

nipper

[Gnuman]

*calls the nurse to give Nipper his medication*

i SWEAR i am going to start beating people with a nerf bat:banghead:

 

what year model engine trannny and milage are on the car. We cant do S**T without this information.

 

 

nipper

 

Nipper, we actually can do s**t without the info. We simply cannot do much more. There are far better reasons to beat people with nerf bats than this. Do not waste them on small stuff.

 

kitsubaru, First off, welcome to the board. To best help you we actually do need the info that Nipper asked for (I will ask more nicely, however ), so we can use that to narrow down the possabilities of what the actual problem may be. For example, if the car has very few miles (less than say 80K), or very high miles (300K plus. .OK, 200K plus ), that info would point in different directions as to what the actual failing component is. Many mechanics make the mistake of just replacing whatever component the computer tells them is bad. That mistake will cost you unneeded money. Nipper (and the rest of us) are trying to prevent that. If you would be so kind to give at least the year, model, and mileage that would help a lot. In general, giving us year, model, what engine you have, what tranny you have (if it is a drive system problem like shifting or somesuch), and the actual mileage on the car, we can be of far greater assistance to you.

 

EDIT: Aha! I see what the problem is. Nipper look at both of our locations. That explains a lot . .

[NoahDL88]

If its an OBD II EJ22, i'd reccomend disconnecting the bolt where the exhaust manifold bolts to the back of the transmission, put a small bolt in there so it dosn't come apart, but keep it loose if you can, i had the very same issue on a 96 OBS, and i took off that bolt, and most of the shaking=>knocking went away.

[nipper]

*calls the nurse to give Nipper his medication*

 

 

Nipper, we actually can do s**t without the info. We simply cannot do much more. There are far better reasons to beat people with nerf bats than this. Do not waste them on small stuff.

 

 

 

EDIT: Aha! I see what the problem is. Nipper look at both of our locations. That explains a lot . .

 

but the nerf bat is sooo much fun

 

nipper

[Cougar]

I would guess the two are related though they may not be. I suppose a intake manifold leak may cause this to happen but I would think the O2 sensor would be showing something also. Before changing anything it may be good to have the exhaust analyzed to see what it looks like and if it indicates a lean condition. If it is ok then I would start by replacing the knock sensor. They do go bad and have a fairly high failure rate.

[blitz]

Noah, please check your PM.

[kitsubaru]

Hello..got a check engine light on. had car scanned. came up as knock sensor...and catalytic conv. both seem to have happened at the same time. soooo... first..haven't had it fixed yet...is this a serious problem for the engine since i've been driving it ? second ..does cleaning the contacts on the sensor rectify anything generally...or should i just replace it ? third......is the catalytic problem ? a result of the knock sensor being problematic ? if anyone can offer any advice ....thank you first post kit

 

 

ok....since i'm new here...first let me thank nipper for the cordial first reply...anyyyway...car is a 99 legacy wagon..automatic...2.2. 120k miles. exhaust smells rich.{is the ecm in knock sensor "safe mode" ? }. also had an oil change recently from meineke {shame on me}....i've red some posts here on the knock sensor acting up from oil changes. problem seemed to happen right around this time.is it possible the o2 sensor is picking up the rich mix and faulting the cat.conv ? tranie only slips a tiny amount only when its cold and only for the first couple of accelerations from stopped. no noise in the exhaust..sounds tight. car slows noticibly quicker now at low speed when foot comes off gas..didn't happen before. so thats it..all this has happened pretty much at the same time. should i try resetting the ecm ? to rule out the oil change ? if i do get a new sensor..what brand ? the oem ones seem to suck from what i've read....is bosch better? ok thanks in advance to any replies. kit {not a native maine-a by the way}

[Gnuman]

Pull the knock sensor and visually check it. If there is deformation or cracking then replace it with OEM. The ECU know how to deal with the signals from that one, and I don't know if others will fit. The OEM one is about $60 from 1stsubaruparts.com . After the Knock sensor is changed, reset the ECU and drive it for a while to see if the cat code comes back. If it does, I would check your O2 sensors before replacing the cat (they are cheaper, actually, and often cause a cat code)

[nipper]

Pull the knock sensor and visually check it. If there is deformation or cracking then replace it with OEM. The ECU know how to deal with the signals from that one, and I don't know if others will fit. The OEM one is about $60 from 1stsubaruparts.com . After the Knock sensor is changed, reset the ECU and drive it for a while to see if the cat code comes back. If it does, I would check your O2 sensors before replacing the cat (they are cheaper, actually, and often cause a cat code)

 

 

i second what he just said now that we have other peices of the puzzle ..

 

nipper

[kitsubaru]

Pull the knock sensor and visually check it. If there is deformation or cracking then replace it with OEM. The ECU know how to deal with the signals from that one, and I don't know if others will fit. The OEM one is about $60 from 1stsubaruparts.com . After the Knock sensor is changed, reset the ECU and drive it for a while to see if the cat code comes back. If it does, I would check your O2 sensors before replacing the cat (they are cheaper, actually, and often cause a cat code)

 

 

 

thanks for the info ...kit oh, by the way can i reset by disconecting battery + ? or is that just on odb1 ? don't i need a scan tool to clear it for odb2?

[kitsubaru]

i second what he just said now that we have other peices of the puzzle ..

 

nipper

 

 

thank you nipper kit