Lambda Sensor Replacement - Hypermotard/Hyperstrada 821

So I have had a CEL on the 821 for a while. I had the code read and it said front horizontal lambda sensor or something along those lines. I read that the threading is the same for most modern Ducatis so I figured instead of spending $300 + on a new sensor from Ducati I could buy and wire one in.

I got one for a monster 821 thinking it'd be the closest save for a completely different fitting. I also found one for a 939 that looked on paper like the same connection. Figured if it didn't work I could use a spare for the 939 SP. Well, they do all thread in, but the sensor bit is different (pics below, smallest is the hyper 821, next in size is the 939 and the biggest one is the monster 821).

So the question is, can I really wire in any old 4 wire sensor or am I going to have the bite the bullet.

Second question is there any way to test a sensor before I cut and splice wires. Basically is the CEL going to clear as soon as a good sensor is connected and sending signal or does the sensor need to be installed and the bike ridden for a bit?

I noticed when I removed the sensor on the front header it was coated in white dust (oxidation?) so I cleaned that off and installed it again hoping that'd clear things up, no luck.

Finally any idea how to get the heat shield off the rear header without removing it from the engine? There is one allen bolt that I can't seem to get to as the frame is blocking access. Figured I should pull the rear sensor just to compare it to the front one.

Thanks in advance, as always.

pics..

I bought a pair of 2016 Monster 821 sensors. I didn't swap on a recent garage day because the wire colors don't completely match. Our OEM sensors have 4 colors and the Monster sensors only have 3, with 2x gray wires.

I didn't see the need to remove rear heat shield to pull the rear lambda. The rear does require a 14mm sensor socket with the wire groove.

gatdammit said:

I bought a pair of 2016 Monster 821 sensors. I didn't swap on a recent garage day because the wire colors don't completely match. Our OEM sensors have 4 colors and the Monster sensors only have 3, with 2x gray wires.

I didn't see the need to remove rear heat shield to pull the rear lambda. The rear does require a 14mm sensor socket with the wire groove.

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The Monster owners manual doesn't state the wire colors for the sensor itself, but you can use the wiring diagram to compare to ours to get it right.

Ducati has the owners manual on their site, with nice wiring diagrams in them.

Clicky: https://www.ducati.com/ww/en/service-maintenance/owner-manuals

Sensor socket, that's definitely a thing I need! As for the wiring, sounds like that can be figured out, but should I be concerned about the different size and profile of the sensor or is does that not matter for a narrow band sensor?

Somebody on here swapped out Monster sensors. They worked.

gatdammit said:

Somebody on here swapped out Monster sensors. They worked.

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Sweet. I'm going to give it a shot this weekend. I searched around here but I guess I may have missed that thread, appreciate it!

If you figure out the wire pairing, please post. My monster sensors have White/ Black/ Grey/ Grey. The OEM's are White/ Black/ Blue/ Grey, i believe.

Will do, didn't get to it this weekend as jetting work on the dual sport bike ate up my Sunday afternoon.

gatdammit said:

If you figure out the wire pairing, please post. My monster sensors have White/ Black/ Grey/ Grey. The OEM's are White/ Black/ Blue/ Grey, i believe.

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The stock sensor side wires are Purple / White / Gray / Black.

I believe it goes like this:

Purple - White Heater
White - White Heater
Gray - Black Sensor +
Black - Gray Sensor -

I have connectors and pins coming to try this myself.

Thanks, Dragoon.

I wired up as I said, and get a check light with the sensor unplugged and goes away when replugged.

Awesome info, thanks!

No problem. Verified with my rapid bike and everything appears to be in order.

Fantastic info. I need to do this but didnt want to spend all that money on the same sensors. Which ones did you end up using? I have had mine unplugged for over a year. You can tell something is odd under 4k rpm but other than that it runs fine.

dragoontwo said:

I wired up as I said, and get a check light with the sensor unplugged and goes away when replugged.

Click to expand...

Did you have any symptoms before the swap? CEL, rough running, backfires on decel?

gatdammit said:

Did you have any symptoms before the swap? CEL, rough running, backfires on decel?

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I had a cel from a bad sensor. I haven't given it a test ride yet to fully clear it. One of the sensors I got had a broken wire that I have to fix. I just got the Monster 821 sensors.

dragoontwo said:

I had a cel from a bad sensor. I haven't given it a test ride yet to fully clear it. One of the sensors I got had a broken wire that I have to fix. I just got the Monster 821 sensors.

Click to expand...

Was it an always on CEL, or did it pop after the engine temp started to rise? Did you also have "ERRORS"?

Depended on the day. Sometimes on from the start, sometimes after warming up I would get a light with "errors".

I have a similar problem on my Hyper. The local Ducati Service centre diagnosed and said that i have O2 sensor on my horizontal cylinder that's not working. A pair of OEM sensor is mind numbing INR 35000 i.e. 480usd + Labour.
Can anyone help with an equivalent sensor from Bosch or NTK that is an equivalent. I have done a bit of research to understand that the stock sensor is 4 wired.
How do i match the wire colours on these sensors with the OEM sensor colours. i believe these are different.
any advice or help will help me save some bucks. i have a good electrician in my office who can help me do the wiring.

A stupid question, what is the full form of CEL.