Im looking at 2 knock sensors online at Auto Zone. They are both Duralast, are listed as part numbers SU 7012 and SU 7015, and look identical other than 7012 has a white stripe on the cable. Connectors and heads appear identical. 7012 is listed as sensor for 2004-2007 while 7015 is listed for 2001 model XJ8. The major difference is 7012 is 30.00 and 7015 is 103.00. Does anyone know if there is any operational difference between the 2 sensors?

 

Quick follow up for any interested or looking for knock sensors
I had to wait a few hours for the part to truck over from the hub, and despite the picture provided I was sure I'd find something that had been mislabeled for 30.00.

What I got was Auto Zone part SU7012 Duralast Knock Sensor
I've had a few others inspect both parts and we all agree it is exactly the same part with the following exceptions.
- New Part has an applied white marker stripe on part of the insulating sheath on the pigtail. Original and photos of replacements do not
- New Part has approx. 3" longer pigtail length.

I may have a non-original part that I'm attempting to replace but each part is identical down to the Denso markings and ribbing on the insulation where it's molded into the head. Connector and wiring are all exactly the same.

After researching a bit earlier today, I may just have an issue with the sensors being over torqued (I'll test that theory later) but I also am led to believe that all the piezio crystal sensors operate on a common voltage (unless manufacturers are tuning crystals for independent makes and models). With that said, I cannot see how this new sensor will not function with the same specs.

I'll test it before I make a final conclusion but based on what I'm seeing so far I'll be ordering an additional 30.00 sensor to pair up with this one.

Somehow I just cannot get the picture of an assembly line with someone in a hairnet sitting at a junction in the conveyor belt pushing all the sensors with white marker to one side and putting the non-marked ones in a bin with a big smiley face on it.

 

If you read sensor documentation, the manufacturers claim the sensrs are mechanically tuned to match a specific engine. That said, I cannot believe that the 4.2 engine has appreciably different resonances from our 4.0 ones, so I have used the later, cheaper sensors and after many miles have had no apparent problems, codes, or indications of engine knock or pinging. Many others here report the same.

 

Thanks for the input. I tried Googling Knock Sensor Specs, and scoured detail sections on everything I was pulling up yesterday and all I was getting were links to "How to change" video's and disclaimers from manufacturers stating that they "strive to put all effort into producing quality products" never could find anything specific unless I searched troubleshooting topics. Other than a few resistance readings to pursue on the backside harness I never found anything more than the crystals produced 4.5 volts when resonating.

I was getting a recurring reduced performance light with no CEL. Then all of a sudden it would throw a code which was always P0333. I pulled both original sensors, and cleaned the block and reset at proper torque, which worked for about 3 blocks before recurring. I then attached the new sensor on Bank 2 and its been clean on test drive and a number of trips today. Ran back to Auto Zone and ordered a second on the first trip this morning.

 

So are use saying you replaced knock sensor SU7015 with a SU7012 and it works just fine?

 

yep - It SEEMS to. No codes, no apparent ping or knock. Many miles later.

 

Yes I have installed a Duralast SU7012 in place of the original existing knock sensor. It's been in for the last 4 days and seems to be doing fine. Im going to pick up a second today so I have the same on both sides.

Not sure if the original was an SU7015 which is part number specified in a search for 2001 XJ8 on AutoZone website.

I will note that I did this after concluding that the sensor I had was faulty which was resulting in false readings. I have no sign of actual ping, and could swap sensors and get code for the other side.

I'm not experiencing any issues and it appears others have done the same without issue but I have to pass on that following my lead is at your own risk. Just passing on my experience.