Hey guys,

I'm curious on two things.

1) are there "specific" O2 sensors for Upstream and Downstream, or do I just go buy 4 sensors and put them in?

Sometimes I see them labeled as Upstream and Downstream, or some indication that they are for lower right and left, or even upper right and left, and the price differs for the same brand. It makes me wonder if there are 4 completely different sensors I need to get or if I need to make sure I get 2 lower and 2 upper, or if it just doesn't plain matter.

2) what is a reliable recommended brand? There are so many and as much as I'd like to get NGK, ones like Bosch and other standard replacements are less. I don't want to be replacing them in 20K miles so I'd appreciate your recommendations.

As always I apologize if this is a repeat post . I did some searching and just didn't find anything that really touched on my question.

Thanks!

 

The upstream sensors (between the engine and the catalytic converters) are the one's that do all the work so it's best to replace them with quality parts. I bought Denso's on Amazon for $63 each. They cost a little more because they are 4 wire sensors with heaters in them that come up to temperature very quickly to help the engine keep the fuel mixture correct. Each one has a different part number because the length of wire coming out of the sensor to where it plugs into the wiring harness is different.

The downstream sensors (in the middle of the catalytic converter) just let the computer know when the catalytic converters are getting clogged and are much cheaper. Got Bosch units on E-bay for $40.

 

Search:Oxygen Sensor part numbers user:Thermo

 

ugotmale, there is a big difference between the upstream and downstream oxygen sensors. You can physically mount one where the other goes, but your engine may not like it.

Check out: https://www.jaguarforums.com/forum/x...umbers-110142/

That has all the part numbers you need. With this all being said, you are going to find oxygen sensors that are $200 each, and you are going to find some that are $20 each. I can not advocate using the $20 ones for the basic reason that you have to splice the wires together to make them work and unless you know what you are doing and have some special stuff, it will lead to more problems later than you are fixing in the immediate time. As for the $200 ones, well, they are just being greedy and you can ignore those. You should be able to find some brand name O2 sensors for under $100 each (ebay has a bunch in the $70 range delivered to your door for the upsteam sensors and the downstream ones for $45 delivered).

 

Search the web for:

Downstream Sensor: Denso 234-4798 (after market) or C2S38497 (Jag Part#)
Upstream Sensor: Denso 234-9029 (after market) or C2S51801 (Jag Part #)

Denso is listed as an O.E. Manf for the Jaguar X Type 02 sensors and recommended by many, especially for upstream sensors. I have found the Denso upstream for around $68 and Denso downstream for $48 on e-Bay (shipped).

I also heard that it is advisable that you replace both upstream and/or downstream at the same time (i.e change same types at same time).

If you are getting plugs changed, it is a perfect time to get access to the Bank 1 sensor located between the block and the firewall changed, since you need to remove the intake manifold to get to the rear spark plugs and 02 sensor (just a thought....)

Hope this helps.

 

Great feedback from all of you thanks!

 

Do you think you would be able to reach Bank 1 sensor between block and firewall w/o removing the intake manifold ? If not - how big a deal is it to remove the manifold ?

 

I did mine with intake on, had to cut the wires off the top of the sensor and slide a long closed end wrench on it to get it to turn loose.

 

How did you access it with the intake on - from the bottom of the car ? Anything else you needed to remove to access/replace the o2 sensor in bank1 ?

 

Got it from the top. The area above the transmission has enough room to get a wrench on it.

 

In case you ever want to get to the rear plugs or remove the intake manifold, this is a great link. (Thanks to rhriczko)

https://www.jaguarforums.com/forum/x...nge-faq-48128/