[2TrakR]

Hit limp mode today. Did it twice in a row after rebooting. Code was P0167. Not finding anyone having mentioned this code previously. What's the thoughts on bad fuel being the culprit? We added half a tank of "ethanol free 90" from a station that probably does not sell much of that flavor. Not blaming "rec fuel", but do suspect this particular batch.

So, about 80 miles into 110 mile run. In the mountains of WV, about as far from truck/roads, was turning around and it sputtered a bit and then limp mode. Shut it down, did a quick visual to see if a stick or something knocked a connector but no dice. Ran OK for a couple minute and then back into limp mode. Pulled the code and then looked close at the O2 sensor (all visually good). Cleared the code and took off after 5-10 minutes of futzing with stuff. Was good to go for the remaining 20 miles, though I was being slightly easier on it.

We were 1/3 into the tank of rec fuel ( 4 gallons) at the time. That was the only item; temps were fine (80) and was not overly muddy/wet.

Code is P0167 Heated Oxy Sensor Heater Circ (bank2, Sensor 3)

The wiring/harness to it were snug, again no visual. Guess it could be a genuine failing sensor. Probably need to order just to have it "in case".

2018 Mav Trail 1000

 

[10mm_]

I would be inclined to think it's not the fuel since that code is for the O2 sensor HEATER, not the sensor itself showing out of voltage range lean/rich.

I would replace the sensor and see if it comes back, and double check the wiring again. I don't think the heater would have been operating if you had just driven 80 miles so it could be a short (either inside the sensor or in the wiring) that triggered the sputter/limp mode.

 

[2TrakR]

I'm only finding one part associated with the O2 sensor, that being 707600872 Oxygen Sensor. Nothing about a separate heater. I have to presume the code refers to the O2 sensor and/or the heating function thereof, but it's just one item. Unless there's something else on the cylinder that I'm missing. Presume this is just the O2 sensor on the exhaust... Have to admit I don't know what the "heater" function of the sensor is for, if it even has that. Might be generic terminology from BRP for that code that does not apply to this specific unit.

 

[Turbo392]

O2 sensors typically have a heater built into them to get them hot as quickly as possible each time the engine is started. 4 wire sensor, 2 for heater circuit and 2 for the signal. Some older vehicles have 3 wire sensors, still with a heater. The computer knows if this heater circuit is shorted out or open.

 

[2TrakR]

Seems weird that a heater short/open would throw the machine in limp mode when the machine is easily at operating temp, has been and had also been running for about an hour. I can see throwing a code, but putting it in limp mode seems like poor engineering. We would not have been able to drive it out from where we were in limp mode.

I'm sure it's like our newer Ford and GM diesel trucks; when the heater element fails in the DEF tank, it throws the whole system in "DEF Fail" mode and will start derating the truck until you are dead in the water. Even though the heater element is to keep DEF from freezing and all of the heater element failures I've encountered were in the summer (no chance of freezing DEF then).

Too bad the aftermarket doesn't offer a magic box that you could override limp mode and take your chances of a catastrophic engine failure.

 

[10mm_]

I'm only finding one part associated with the O2 sensor, that being 707600872 Oxygen Sensor. Nothing about a separate heater. I have to presume the code refers to the O2 sensor and/or the heating function thereof, but it's just one item. Unless there's something else on the cylinder that I'm missing. Presume this is just the O2 sensor on the exhaust... Have to admit I don't know what the "heater" function of the sensor is for, if it even has that. Might be generic terminology from BRP for that code that does not apply to this specific unit.

That's correct, the heaters are not separate they are internal to the O2 sensor, but bad fuel might cause a funny oxygen level reading but it is very unlikely to cause a funny heater circuit reading.

Heaters in O2 sensors are in place because the sensor doesn't function at full accuracy until it is warm, if the designers rely on the exhaust gases to heat the sensor it takes longer for the readings to be accurate and longer for the machine to swap over to the closed loop maps (in other words if the sensor wasn't heated it would take longer to start working).

How much is the O2 sensor and how hard is it to access? If those answers are modest then I would just replace it for peace of mind and move on.

 

[10mm_]

Seems weird that a heater short/open would throw the machine in limp mode when the machine is easily at operating temp, has been and had also been running for about an hour. I can see throwing a code, but putting it in limp mode seems like poor engineering. We would not have been able to drive it out from where we were in limp mode.

I'm sure it's like our newer Ford and GM diesel trucks; when the heater element fails in the DEF tank, it throws the whole system in "DEF Fail" mode and will start derating the truck until you are dead in the water. Even though the heater element is to keep DEF from freezing and all of the heater element failures I've encountered were in the summer (no chance of freezing DEF then).

Too bad the aftermarket doesn't offer a magic box that you could override limp mode and take your chances of a catastrophic engine failure.

The problem with not putting it into limp mode is there is no incentive to fix it. You can't think of these things from your personal perspective, where you will include characteristics like pride and intelligence and logical thinking. You have to look at it from a statistical perspective, imagine 10,000 people with SxS that have the same problem. What % of them would fix it right away after they used their override switch to get home? And what % would flip that switch on the first time they have a problem and never turn it back off or fix anything until the machine gave up the ghost? Probably quite a high number. Too much liability.

Can Am didn't build this machine for ME, or for YOU. They built it for the masses, and the masses are kinda dumb. That's why many of these systems seem overkill when it comes to preservation.

 

[2TrakR]

How much is the O2 sensor and how hard is it to access? If those answers are modest then I would just replace it for peace of mind and move on.

Already have the sensor on order. ~ $85

 

[Turbo392]

The limp mode is to protect the catalytic converter from melting down and causing a potential fire. If there is any chance of inaccurate o2 sensor readings it will protect itself from you.