after having my check engine light read, i was told i needed an oxygen sensor.

the location was bank 2 / sensor 2


is this the passenger side, after the cat??? if not can someone tell me the location



thanks

 

Anyone??

Thanks

 

That's correct.

Bank 1 = Left Side (Driver Side)
Bank 2 = Right Side (Passenger Side)

Sensor 1 = Rear of Exhaust Manifold
Sensor 2 = Rear of Catalytic Converter

So 2/2 would be behind right cat...correct.


EDIT: Clarified Left and Right

 

Right Meaning Passenger Side Correct

 

US-centric eh? So on a RHD car in the UK, it would be the one on the DRIVER'S side - i.e. when looking from the front of the car, it'd be on the left? And Bank 2 Sensor 2 would be the one just to the right of the leftmost pock-marked heatshield? I need to change mine urgently (MOT required) and want to be sure I replace the correct one! I'll take a photo for further clarification and re-post here....



Would this, in the centre of the image, be the Bank 2 Pre-cat O2 Sensor ?

And if so, could someone please post a corresponding image of the Bank 2 Post-cat sensor, i.e. Bank 2 Sensor 2 ?
A picture is worth a gazillion words, and may put an end to many debates regarding left/right/front/rear/pre/post etc.

 

I have found this answer on IFIXIT.COM, courtesy of Ian Hunter: https://www.ifixit.com/Answers/View/...cation+removal

Would the Crossfire gurus agree with those diagrams?

Thanks.

 

The one in your photo is Bank 2, sensor 1 . The bank 2, sensor 2 is under the car behind the cat.

 

Thanks Zeracer. It's had me very confused, as there seems to be contradictory views on which side is Bank 2. If it'd been one of the sensors in the engine bay, I'd change it myself but as it's under the car, I think I'll leave it to a professional with ramps or a lift.

 

Actually, I'm still confused. An earlier post in this thread states Bank 2 is "right, passenger" side. Which would be UK driver's side. My photo shows UK passenger side. Is the engine bay layout reflected left to right when the steering side is changed?

 

Now, that is a good question. I have no idea with RH drive vehicles. A Mercedes mechanic should know.

 

O2 sensors are numbered by reference to the #1 cylinder. Has nothing to do with right or left hand drive vehicles. When you are setting in the car left is your left and right is your right.

Post number 3 is incorrect.

When you are setting in your car the M112 engine #1 cylinder is on the right; O2 sensor bank one is on your right, Bank 2 is on your left. The valve covers have the cylinder numbers indicated on them Look for the numbers on the valve cover to confirm.

 

Thanks. That makes sense. So, if you look at the diagram of the rear sensors linked to in post #6, the Bank 2 Sensor 2 would be the item numbered 4, yes?

 

The answer is "no". THAT is why they are referred to as "Bank 1" and "Bank 2", not "passenger side" or "curb side", as those definitions change around the world.

One way to prove me right (as if there is ever a reason to): unplug one of the forward sensors (they are easy to get to). Now, drive the car.
THen, read the code that is generated and compare that code to the master list here on the forum - and you will know the answer to your question!

List is here
https://www.crossfireforum.org/forum...-dtc-list.html

 

I edited my post.

Read it again!

 

If you're going to change one, why not change all four of them?
They will all burn out eventually. Labor wise it will be less expensive as well.
Just my two cents.

 

Thanks Pizzaguy. I read (and re-read) it, despite having every faith in you I'll advise the mechanic (at a local independent) to replace the one on the same side as my photo, but post-cat and I'll update here afterwards to confirm the dreaded code has been vanquished.

 

Given the age of our cars, the above advice sounds like a good idea to me....

 

I mostly agree with your sentiment, Depending on the price of the repairs (parts & labor), it is a personal decision to replace something that works vs throwing parts at it hoping to not have another 'failure' with three that work, and works fine.


.

 

Happy to report that the bad one has now been replaced and the MOT has been passed, so a few more months of motoring is possible before the snow arrives
Thanks everyone for your guidance.

 

Thanks for the update.