Author Topic: code 1226 knock sensor #2 (Read 9576 times)

JoeDellio · « **on:** February 13, 2009, 02:09:43 PM »

Finally got the peda trick to work, kept giving me 1226 over and over. Im guessing this would probably have to do with my rough idle? How hard is this one to change, I cant tell what the haynes manual calls the #2 knock sensor. I thought there was only 2 (but code numbers show 4 knock sensors) between the cylinders on the intake side of the head.

ClubSport · « **Reply #1 on:** February 13, 2009, 07:58:31 PM »

http://forums.bimmerforums.com/forum/showthread.php?t=758138

Mine turned out to be an O2 sensor. Don't be to quick to do the knock sensors, they are a pain on a stock M42.

JoeDellio · « **Reply #2 on:** February 14, 2009, 04:41:47 PM »

Thanks, Im gonna try a used sensor from the junkyard first, and just buy a new O2 sensor at the same time. I will put them on seperately to see which it was though.

ClubSport · « **Reply #3 on:** February 14, 2009, 06:17:44 PM »

I've still got the two knock sensors I took off when diagnosing the problem. They have 85k miles on them.

Are your symptoms the same as mine were? CEL comes on after a while on the highway?

JoeDellio · « **Reply #4 on:** February 14, 2009, 07:24:22 PM »

My CEL comes on when driving at cruise speeds. If I take my foot off the gas it goes away, and then comes back after sometimes only a minute. Then when my car idles it runs super rough like its cammed out, but it doesnt sound good. The light will pop on sometimes when I am idling and wont go away until I get into throttle and then let off. My car only idles like crap like that sometimes, well most of the time, even if the CEL is off. I figured I need to clean my IACV out, but the CEL has to be telling me something. Sometimes the car bogs out when first starting it up and trying to drive, but clears out when I get on it.

Once I replace the knock sensor, will the ECU then give me other codes? PM how much you would want for your sensor, there is a yard by me that has a complete e36 m42, but if your price is right its worth a shot.

ClubSport · « **Reply #5 on:** February 15, 2009, 09:23:27 AM »

Don't replace your knock sensors yet. Those are the exact symptoms I had and it was the O2 sensor that fixed it.

JoeDellio · « **Reply #6 on:** February 15, 2009, 12:40:39 PM »

And you had a late M42 right? Im gonna go buy a bosch universal O2 sensor then, and see if that does it. I acutally have a good one from another vehicle here I could try. Do these cars have front and rear sensors, or just a rear? If the problem persists I will contact you for a knock sensor.

I just got under the car and saw the one before the cat. I cant tell if it is a 3 or 4 wire sensor. I thought all the universal bosch's came with 4 wires. I will have to search how to wire it if that is the case.

colin86325 · « **Reply #7 on:** February 15, 2009, 05:01:57 PM »

The E36 M42 has 2 knock sensors.

JoeDellio · « **Reply #8 on:** February 15, 2009, 06:26:17 PM »

Quote from: colin86325;66579

The E36 M42 has 2 knock sensors.

I meant 1 or 2 O2 sensors. I see the M42 has a knock sensor between cylinders 1 & 2, and one between 3 & 4, but WHY is there codes for Knock sensor #3 and knock sensor #4?

ClubSport · « **Reply #9 on:** February 15, 2009, 11:43:50 PM »

There is only one O2 sensor, ahead of the cat. I got a Bosch part number 13231 O2 sensor at Autozone which plugged right in.

Yes, my M42 was one of the last: 9/95

JoeDellio · « **Reply #10 on:** February 16, 2009, 12:43:58 AM »

Quote from: ClubSport;66599

There is only one O2 sensor, ahead of the cat. I got a Bosch part number 13231 O2 sensor at Autozone which plugged right in.

Yes, my M42 was one of the last: 9/95

I checked advance and all the ones they have are for $70 and up. I found universal ones for $32. I just gotta check if mine is a 3 or 4 wire tomorrow.

JoeDellio · « **Reply #11 on:** February 16, 2009, 09:25:05 PM »

UPDATE: I got under the car today to confirm that the sensor has 4 wires. I also found out that it was loose, extremely loose to where exhaust was leaking out and I could screw it in a couple turn with my fingers.
I tightened it up and to my surprise the car runs worse now. I thought this was odd. I ordered a new sensor today so I guess I will start from there.

Jimmy Lewis · « **Reply #12 on:** February 19, 2009, 08:26:13 PM »

Make sure the O2 is tight in its bung and then unplug it and see if there are any changes in the way the car runs. See if it throws you an O2 sensor code, you never know. I bought my universal bosch for 25 bucks shipped on ebay and it looks exactly like the one that came out of the car stock, you basically pay 50 bucks for the plug on the other end.

JoeDellio · « **Reply #13 on:** February 19, 2009, 11:07:54 PM »

Quote from: Jimmy Lewis;66856

Make sure the O2 is tight in its bung and then unplug it and see if there are any changes in the way the car runs. See if it throws you an O2 sensor code, you never know. I bought my universal bosch for 25 bucks shipped on ebay and it looks exactly like the one that came out of the car stock, you basically pay 50 bucks for the plug on the other end.

Yeah the O2 sensors with a plug are such a bunch of bullshit. I dont think Ill ever buy a "vehicle specific" sensor ever again. But I did the test you talk of before, and it runs pretty good with it unplugged, but.... its just hard to tell because the lopey idle comes and goes like an erection during an episode of a Baywatch re-run; it actually runs a little better when the air is on, but I think thats just because the IACV kicks it up a notch.

Nevertheless, I will have my new O2 sensor next tuesday, and all my gaskets to do a IACV cleaning and a "Medusa" delete. That dirty bitch.

JoeDellio · « **Reply #14 on:** February 26, 2009, 03:18:20 PM »

Installed O2 sensor. No changes. Gonna replace knock sensors.