Hello friends and neighbors - first real post here so please bear with my ignorance. My '97 XJ6 has been throwing O2 Sensor codes since I had the exhaust replaced from the manifold back - all new everything except the left muffler. I replaced all four sensors with Chinese cheap crap which didn't work as codes were still stored and active ( I'm sorry I don't have the exact codes right this moment). So silly me went looking for sensors and found they are impossible to get in the US and UK companies won't ship to the US. The car runs perfect and does not need to pass emissions inspection in NY due to age. I did purchase two "good working" used sensors online but am holding off on installing them. Can anyone who has experience with this issue provide some guidance....should I say screw it and drive it until performance indicates trouble or chase down the problem with associated expenses? I am searching the forums for info as I should! Thank you for your time and experience. John

 

As you have probably noticed the O2 sensors are titania based and not the other more common

The sensor pigtail wires are galvanized and brittle if the sensor is not installed with care not to twist the pigtail wires

On the 4 O2 sensor system only 2 are used for engine regulation so you have some swapping options but you may have a 420 or 430 code for catalytic efficiency as the fwd 2 compare to the aft 2

There is one fuse for all 4 sensor heaters so they will read correctly

There is a ground stud on the rear engine firewall to prevent error signals from being intruduced into the O2 sensor signal

Bosch # 13789 is a connector ready replacement

The O2 sensor connectors can be easily swapped and this causes problems

 

And this what I hoped this Forum would be like! So it sounds like there could be many causes of a "false" problem that might infact be inaccurate readings or a mechanical fault with the sensor itself vs an issue with actual emissions if I'm reading your reply correctly. And as far as the part - I have searched everywhere. I've learned it's an obsolete part and may not be being produced anymore. Thank you very much... John

 

With respect to the emission machine testing your actual engine against it may be using or defaulting to the standard type of sensors and in communicating through the mechanic and in the end you have bad information

The X300 sensors operate in a totally different manor

But you have codes ?

See page 80

801S TITLE (jagrepair.com)

 

Downstream sensors do the heavy lifting (on the AJ16 engined XJS), if you were going to swap two, those would be the ones to do. The upstreams are used as a check.

Now that being said, can you check, using OBD2, if the car is going open loop? If the sensors are out of range, the car will remain in closed loop and fuel the engine based on a preprogrammed system, which would fool you into thinking that the car in running fine, when in fact it is not.

 

Quote:

And as far as the part - I have searched everywhere. I've learned it's an obsolete part and may not be being produced anymore.

Use the Bosch 13789 as previously mentioned. Readily available, reasonably priced.

If the sensors are NLA from Jaguar it is probably due to lack of demand....which in turn is likely due to the outrageous pricing

Cheers
DD

 

On chasing a part for my 1996 X300 at our local Jaguar dealers I was advised that Jaguar consider the car to be "obsolete" and would not be supported with spares.
Go for aftermarket parts from reliable sources.
Doug's advice is as usual spot on

 

I suppose once ownership of the brand changes there is unfortunately less interest form the owners of the brand in supporting models from the previous era.

 

For the time being Jaguar still offers a lot of spares for the X300 but I've noticed increasingly more "NLA" listings as the years go by.

I sold my X300/XJR some years ago but even then there were XJR-specific parts that Jaguar was no longer selling. I think the X300/V12 owners are facing the same thing nowadays.

Every manufacturer faces the same decisions on when to relegate xxx-part to "NLA" status. It takes time and effort ($$$) to maintain a replacement parts regime. Supplier contracts expire and decisions must be made. Or.... vendors are no longer interested in supplying the part, or even cease doing business. Then a new supplier must be found and vetted.

Surely consumer demand...and company profitability... are big factors in the decision.

Cheers
DD

Cheers
DD

 

Don't forget about the cost to store the part...waiting for buyers that may never come?

 

So she is throwing P1185 and P1186 for the O2 Sensor heater circuit.

 

New oxygen sensors are in your future….

 

If only I could find some.......everything is out of stock, back ordered, no longer available etc etc.....

 

Your heater power is the green colored in wire in the pic as fuse XLooking for the one fuse for all 4

And a pic so you can put a meter on the heaters inside the sensor

As for replacement you may have to visit a salvage yard and by using oxegen consuming flame torch you can test them at the yard

The yard I visit has a habit of cutting off the pigtail wire that can not be repaired

So you would have to be on a call list as sone as a X300 arrives if that's how yours operates

Editing

 

Fuse is # 14 right engine bay fuse box

The test point on the 4 sensor connectors are Blue / Pink ( UK )X and White / Green ( WG ) color

 

Yeah the Walker brand sensors still appear to be unobtainium from Rock Auto and Amazon still. No luck on the Bosch ones either. Tried an eBay seller in Europe and they refunded me 2 days later due to no stock.

I wound up finding an eBay seller with ‘FAE’ brand sensors for reasonable pricing. Part # 77185. They came from Poland or Lithuania. Shipping time to the states wasn’t too bad. I have not installed them yet, so I can’t speak to functionality, but they appear to have the correct design and connector.

Hope this helps - good luck!

 

Found them! Thanks for the info......I don't know why I didn't find them while I was searching. We will see. Thanks very much again

 

A semantic point perhaps, but I think you are mixing up open and closed loop.

 

Doug's comments are spot on, one cannot expect to drive around in an almost 30 yr old car expecting to obtain parts readily nor expect the local dealer to have them on the shelf.
This is just part of the game if running these older cars. One learns to be very skilled & patient on Google search.
I can only speak for the situation here in Australia, but only recently in July I purchased two new NGK NTK O2 sensors part no OTD3J-5B1 as originally fitted to the X300 from a parts seller "Rolan-Australia" for A$319. At the time there were several sellers listing them and I actually had a choice.

John Herbert ( Peregian Springs, Qld Australia)
1996 XJR

 

BlackSpeed66 gave a good ray of hope. I too will be buying from Lithuania. I just hope they are the titania type. Which seller did you use on Ebay, Gene? I have one X300 that needs one and another that needs two. Fingers crossed.