At 127k mi I want to change the O2 sensors on the Jag, mileage is down to 18 mpg in town heavy mixed driving; used to be 20+.

Jag have done a great job of hiding the sensors away behind heat shields and plastic bits.

The front muffler has to come out the get at the sensors from beneath. Any ideas how I can do this in my driveway?

Thanks,

Dan

 

Which ones do you need replaced?

 

All four.

 

If you have mileage issue I would just replace the 2 upstreams, it's really not that hard. The one on the passenger side is very easy, just use a 22mm open end wrench to remove. The one on the driver's side you can move the water reservior to the side, tie it with a coat hanger to the hood strut so it's out of the way, remove the heat shield with a 35mm torx bit then remove 2 (not 3) nuts that hold the heatshield bracket onto the exhaust flange. to remove the sensor use a 22mm open end and a 23mm open end. Use them alternately as each one can only unscrew the sensor a little at the time. Reverse process to install new sensor.
I got my Bosch sensors from Amazon for $60.00 each, works real nicely.

 

Thanks, Icebreaker!

I wasn't looking forward to taking the exhaust off!
Is the coolant reservoir drained before being tied off?
Not quite sure about using a 23 and 22 wrench, is the larger wrench to get a purchase on the sensor? I have a sensor socket, perhaps that would work?

Got mine at Amazon too, good deal!

Cheers,

Dan

 

The reason I used the open end wrenches is so that I wouldn't have to drop the exhaust if I were to use the O2 socket. The reason for using both the 22 and 23 mm wrech is because one wrench can only turn the sensor a little and I used the little bigger wrench to turn it a little bit more, you just need a little patience as you can only turn the sensor a little at a time but this way you won't have to drop the exhaust. No I didn't disconnect the reservoir, just tied it out of the way.

 

Got it!

 

all four on mine said they are bad do u have to change all of them or just to up stream? or is computer bad?

 

i cant find them on amazon.com and if i do find them will the plug fit or do u have to cut and crimp them? and how do you know which wires go where

 

Clear the codes. Perhaps they will not come back!

Check out the part finder on Amazon auto section.

 

it says all four are bad , maybe my computer is messed up?

 

Danny,

Here's the link:

http://www.amazon.com/Bosch-13441-Ox...359615&sr=8-12
By the way, if your upstream O2 sensors are bad it is possible that the downstream ones could also show bad as it is reading what the upstream sensors are adjusting which may not be correct as they are bad.

Alan.

 

I agree with Icebreaker, change the upstream ones, clear the codes and see what comes back. The upstream ones are under a lot more strain being before the cat converter and usually go out first. Those ones on Amazon look like a good deal.

 

one more question! on amazon it says that, that wont fit, they could be wrong also, is that the same part for the top and bottom o2 sensors?

 

Go to amazon and select Automotive department. Type in oxygen sensor. At the top of the results is a little box "Part finder". Select your car and all the sensors fitting your year and model will be shown. It's a matter of going through them to see which ones fit either the top or bottom. Generally only two Bosch sensors (one for the top and one for the bottom) will be shown.

 

Dan R/rawdanny, what year are your Jags? In MY '99 Jag changed the upstream sensors to a constant-voltage linear type which I believe is Bosch part 15048 or Walker part 250-54018. Using non-linear sensors pre-cat in a MY '99 or later V8 will certainly confuse the EMU completely.

Jim

 

The part finder tells me that Bosch 15627 is the upper sensor for a 2000 XJ8.
I've got two at home unfitted, they look like an exact replacement.

 

P.S. The parts finder indicates that Bosch 15048 is the one for a 1999 XJ8.

 

Thanks, I think that's what I said

The key thing is to put the time in to identify the correct sensor - there are so many different types, I looked for ages before finding enough information to be able to identify the correct replacement.