If you go to densoautoparts.com and search for your car you will see that the part I suggested is the one for you.
I did buy that part and it is the right one (for all cars up to vin M45254)
If your connector is different then it has been tampered with before.

 

A little history of the car may help. My hunch is a previous owner swapped in an el cheapo generic sensor when the original needed replacement. The wiring was modified/butchered to work with an unheated sensor.

The sensor's heating element helps bring the sensor up to operating temperature quickly. It also helps keep the sensor good and hot for maximum accuracy when the exhaust temperature is fairly low, such as when coasting. Code P0153 indicates a slow response from the sensor. This could be caused by a cold sensor.

Why no code for an open heating element circuit? If you unwrap the harness near the sensor, you may find a resistor soldered between the two wires intended for the heating element. Then this was tucked back inside the harness. The computer had been happy because the resistor tricked it into thinking the heating element circuit was intact, so no code for that.

What about the other three sensors? Two wires or four?

 

I have had the car since it had 50000 miles on it. The harness has NOT been modified. Your suggested sensor is NOT the correct plug and is heated. My 2 upstream sensors have 2 wires going into a square plug. The harness is obviously factory on both sides of the engine and the wire /plug mounts and harness jackets are obviously factory and unmolested. I put a rear one(downstream) in it 3 years ago and had no problems specifying one or installing it.

 

tonykart... since we don't know the history and can't see the car first hand... its not obvious to us.

If you only have only 2 wires on the upstream sensors either... its uncommon and we haven't seen that before. Or at some time prior to you owning it somebody hacked it as kr98664 suggested.

About the only thing I can offer is to remove both of the upstream sensors and post pictures here. Maybe that would give some clues.
Also.. I'd look at how fast they swing from high to low. That should confirm that the code your seeing is legit.

You could also remove them and just take them to a autoparts store and get some replacements that physically match. That's not diagnosing but you might get lucky.

 

Well, I think I will buy a bosch 13191 which is a non heated 2 wire. I'll cut my 2 wire loom off the old sensor and solder it on to my new sensor hoping for the best.

 

Something's very odd here as none of the 4.0 cars have 2-wire sensors from the factory.

At least, not so far!

I'm with those who think the car's been modified (that or you've not got the right device or some such).

 

I agree. Someone put the wrong sensor in and probably modified the heater circuit

 

And now the plot thickens. See figure 01.6 in the 2002 wiring diagrams:

http://www.jagrepair.com/images/Auto...x2032002en.pdf


In the front power distribution box, fuse F11 is the power source to the heater elements in the four oxygen sensors. Follow that wire to the right, and notice the little comment at splice PIS4:

"NOTE: PIS4 – Vehicles with HO2S only."


This implies that some vehicles did NOT have heated oxygen sensors. This was quite the surprise, and would seem to infer that I was less correct than usual.

But which vehicles? My best guess is this was only for markets that did have not stringent emissions standards, maybe Central America for example. I can't imagine a vehicle originally intended for the US market would not include this feature. But maybe if you have a vehicle originally sold in another region and then imported in the US. Could that be?

OP, is your car subject to emissions testing? I think if not equipped with heated oxygen sensors, the vehicle would fail the monitor test.

 

If the car was modified, whoever did it was excellent at making it look factory. The wiring is NOT spliced anywhere visible.Both sides look exactly the same as far as age, dust,connector style and the sheathing and insulation as the wires go into the looms. The car is from Salt Lake Utah, has been here for at least 12 years and has always passed emissions and we have similar testing in Salt Lake to California. The vin is SAJDA01P82GM32907. It has square, 4 pin hole connectors of which only the top 2 are used. the wire colors are black with a white stripe and white on the car side of the connector and black and white on the sensor side of the connector. The way the wires go into the looms on the rails looks like they have never been touched on either side. The connectors are black plastic with red locking tabs. and are pinned into mounts aft of the rails with christmas tree keepers that slide into the connectors.

 

Wow - good find.

You could be right.

It will almost inevitably mean that most parts sites will offer the usual parts and thus the OP's problem.

BTW that VIN looks to be 2001MY in Jaguar terms, though I think it makes no difference here.

 

Thanks Jag V8
if we make the assumption that the car is not modified as this is how it appears, it is also safe to assume that mine is not the only one. Your research seems to support this. I think the car was origionally delivered to Ken Garff Jag in Salt Lake, we emmissions test every year, it has always passed easily and it passed again 3 days prior to this event. Rather than plumb 2 heated o2 sensors up stream I am going to buy a bosch 13191 and solder my plug onto its pigtail. This is a nonheated 2 wire standard sensor. I cant find a 2 wire with the correct square connector and I dont want to use a 4 wire with the heat circuit inoperative. All the specs I have been able to find point to 4 wire heated sensors upstream but that is not what Jag did in this car. Part to be here by 9/11. Will install, reset computer and report findings then. Thanks for all the help guys, this is a weird one.

 

I think I'd try that, too. I can't see it causing harm, so long as when monitored it does allow closed loop operation and sane fuel trims.

I hope it works!

 

ha, now I just hope the old one will come out without a battle!

 

As a FYI, Carfax reports that this car appears to be a US model originally sold on 12/22/2001 in Utah; this may be a "49 state" model; I believe that Jaguar went to the stricter California emissions specs across the board with the X202 in 2003.

 

Ahh, a 49 state model, just my luck.

 

thanks for the research help KR98664, it is subtle but does indicate what might be going on.

 

My sensor (a wideband but the same shape I think) was in "tight" (as in: very). I cut the wires so I could use a standard 6-point socket rather than one of the special O2-sensor tools. Applied a jack (gently) to provide torque and left it for a while. Once loose they come out OK.

 

Here's what you need. Never met an O2 sensor this beauty couldn't break loose:

https://www.lasertools.co.uk/product/6098

 

I would like to take this time to apologize to everyone who has spent time on trying to solve my problem. I am a "shade tree" mechanic and I blew this one entirely. The plugs I thought were the o2 sensors at the back of the injector rails are some other system. I got down under the car and my Jag is like everyone elses. 4 wires, round plug,green, plugs in right by the sensor ,denso 2344046 as you told me Leaping cat. I cleaned off the oil, sanded the contacts plugged it back in, reset the computer and poof, no engine light.
Gentlemen, I am so sorry for wasting your time
Sincerely,Tonykart

 

Seen it but not needed so why spend money on it...