Changed Out Oxygen Sensors

[Maximus Gladius]

21 JTR, 3.6, auto, 110k kms (68k miles)

Finally got around to doing the job with my son and it wasn’t so bad at all. Jacked up the front, took off the front tires and wheel well liners and there they are. Easy reach to it all. Definitely helps to have the bent ratchet bar and med and short length torque bar. (32ftlbs)

I had read up on the sensors having a life of 60k-100k miles so mine were already at 68k miles (110k kms) but I wasn’t going to wait for a code and I suspected they weren’t sniffing the fumes as best as they could seeing as how I saw what my oil burnt spark plugs looked like at 60k kms.

After changing my spark plugs back at 60k kms, I installed an oil catch can and I am now catching 200ml in 5000 kms. But that’s been a lot of oil burn, not sure exactly as I’m on my second engine but the oxygen sensors wouldn’t have been changed out so these have 110k kms on them.

I’ve wondered, and we’re about to find out if my speculation is correct or not but I’m thinking because I’m now catching that oil that was headed to the burn chambers, and because my spark plugs are now not burning that oil, by changing the oxygen sensors should increase my fuel mileage. I did take it for a stomp down the highway after the job and it was running absolutely perfect. My reader was telling me the sensors were figuring themselves out and that data wasn’t ready for me when I got back home but I’ll know in short order if my mileage improves.

I’m currently getting 14.5-15L/100 (15-16mpg) on winter gas, 300 lbs of winter weight, recovery straps and tools and 315/70/17 K03’s. So I’m hopeful my theory is correct, I’ll update as I put some mileage on.

The orange/red sensors are the “upstream” ones the cleaner normal looking ones are “downstream”.

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[Duece McCracken]

21 JTR, 3.6, auto, 110k kms (68k miles)

Finally got around to doing the job with my son and it wasn’t so bad at all. Jacked up the front, took off the front tires and wheel well liners and there they are. Easy reach to it all. Definitely helps to have the bent ratchet bar and med and short length torque bar. (32ftlbs)

I had read up on the sensors having a life of 60k-100k miles so mine were already at 68k miles (110k kms) but I wasn’t going to wait for a code and I suspected they weren’t sniffing the fumes as best as they could seeing as how I saw what my oil burnt spark plugs looked like at 60k kms.

After changing my spark plugs back at 60k kms, I installed an oil catch can and I am now catching 200ml in 5000 kms. But that’s been a lot of oil burn, not sure exactly as I’m on my second engine but the oxygen sensors wouldn’t have been changed out so these have 110k kms on them.

I’ve wondered, and we’re about to find out if my speculation is correct or not but I’m thinking because I’m now catching that oil that was headed to the burn chambers, and because my spark plugs are now not burning that oil, by changing the oxygen sensors should increase my fuel mileage. I did take it for a stomp down the highway after the job and it was running absolutely perfect. My reader was telling me the sensors were figuring themselves out and that data wasn’t ready for me when I got back home but I’ll know in short order if my mileage improves.

I’m currently getting 14.5-15L/100 (15-16mpg) on winter gas, 300 lbs of winter weight, recovery straps and tools and 315/70/17 K03’s. So I’m hopeful my theory is correct, I’ll update as I put some mileage on.

The orange/red sensors are the “upstream” ones the cleaner normal looking ones are “downstream”.

Have you ran an octane booster?

 

[Maximus Gladius]

Yes, in winter, but it does not contain MMT. Mostly used for power gain and keeping the injectors clean. I’ll have to cut back a bit.

Running the THINKDIAG+ scan prior to changing the sensors, fuel burn passed and cat temp was normal. I had mentioned that I had no indication anything was wrong, no codes, the exhaust had no smell. I was fully expecting to see carbon buildup at least on the upstream sensors but there was non, wasn’t even a hint of oil burn smell to them.

Back in the summer when I had that misfire in #5 (P0305), it was a bad plug, I pulled that plug and took it in to have the service manager have a look who then asked the shop forman for his opinion and he said “it looks normal to the ones we change out here, in fact we typically dump out the blowby oil that’s sitting up in the upper intake all the time”. This plug only had 60k kms on it. I was certain the oxygen sensors were fouled up too but as I said, the diagnostic showed the burn as normal and passed within the correct parameters.

I’m glad to see the sensors aren’t carboned up but I will have to reduce the boost I use.

Edit: I’m adding in the reason for my using boost is because I take a hit with the change difference in performance between summer and winter fuel. The “octane” boost isn’t changing the 87 to whatever higher number, it is a “power” boost which brings back the power of what I had with the summer fuel. When the fuel is changed to “winter” fuel, I have always lost 2 mpg or 1-3L/100 and using boost gives me those numbers and power back.

 

[KevinC]

It shouldn't take but maybe three startups for the computer to learn the new sensors. The old ones really don't look bad at all. Maybe the octane booster helped?

 

[Maximus Gladius]

The old ones really don't look bad at all.

This is the first time I’ve ever considered oxygen sensors was something I needed to take care of. They were never something I ever thought of. Now I’m reading they have a life that’s only so long but I’m a fan of replacing things that have come to their end or soon will but haven’t blown a code.

I’m glad you think they look fine. I’ll have to run the reader again to see what it thinks of the emissions now.

 

[Rusty PW]

Plugs 5 and 6 are toast. What's the gap on all the plugs?

 

[NVjeff]

Seeing how those plugs look at such low miles makes me think I need to plan on checking mine sooner rather than later.

 

[Maximus Gladius]

Plugs 5 and 6 are toast. What's the gap on all the plugs?

1. .045/1.14mm
2. .045
3, .045
4, .045
5, .050/1.27mm
6, .060/1.52mm

(60k kms/37k miles)

 

[Maximus Gladius]

It shouldn't take but maybe three startups for the computer to learn the new sensors.

Ran the scan tonight and everything passes emissions. Even got down to the end of the exhaust and couldn’t smell a thing.

 

[Hootbro]

What brand O2 sensors did you throw in?

 

[Maximus Gladius]

What brand O2 sensors did you throw in?

OE

 

[Stan H]

What brand O2 sensors did you throw in?

@Hootbro have you tried other brands ? I seen extreme terrain had Bosch brand O2 sensors dont know which of tbe 2 would be for upstream versus downstream though

 

[Minty JL]

@Hootbro have you tried other brands ? I seen extreme terrain had Bosch brand O2 sensors dont know which of tbe 2 would be for upstream versus downstream though

When I change O2 sensors I try to always use Denso's.

Like someone said above.......guess I'll be doing plugs and coils sooner than later

 

[Stan H]

OE

Where did you purchase from ?

 

[Maximus Gladius]

Where did you purchase from ?

Dealership. I had to wait 2 weeks for them.

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