2006 XK8 with 121,375 miles....

I was able to do the Octopus Hose Leaking Norma Connector repair today. I managed to pull the end of the octopus hose out of that Norma connector, then used a big pair of channel-lock pliers to grip and twist and pull the deteriorated Norma connector off of the metal pipe it attaches to. A 3/4-inch by 3/4-inch brass hose barb, a 3-inch section of new 3/4-inch heater hose, and three new hose clamps indeed did the trick....

In order to gain better access to that area, I carefully unscrewed the upper oxygen sensor with my 22mm box wrench. Once I broke the threads loose, I unscrewed it with my hand. I placed a piece of duct tape over its mounting hole so no splashing coolant could get in there. I then wrapped the oxygen sensor and the first few inches of its electrical harness in a plastic bag and twist-tied it up out of the way....

After finishing the new plumbing part of the job, I carefully removed the oxygen sensor and the first few inches of its electrical harness from the plastic wrap, threaded it back into its mounting hole by hand, and tightened it up again with my 22mm box wrench. I concentrated on being careful not to overtighten it. The plastic wrap was slightly wet from splashed coolant, but it did not appear that any splashed coolant reached the wrapped-up oxygen sensor....

After re-installing the air intake duct and making sure that everything was properly back together, I started the engine and let it warm up for about 15 minutes. The good news is that there appear to be no more coolant leaks. The bad news is that approximately five seconds after starting the engine, the Check Engine icon illuminates on the dash. My scanner shows P1646 (along with the expected P1000). JTIS reports P1646 as "ECM HO2 sensor control malfunction for Bank 1 Upstream" for the 2004 XK8 (JTIS only goes up to the 2004 model year). My scanner can successfully clear this code but it returns approximately five seconds after each engine start. I shut off and re-started the engine four different times, cleared the code before each re-start, and the code returned upon each re-start....

Any ideas what may have caused this issue? I believe that oxygen sensor is the May 2005 factory original, now with more than 121,000 miles on it. But I wonder if I somehow disrupted the harness or contaminated the oxygen sensor while making the cooling system repair today....

I cannot see or feel what or where the other end of that harness plugs into. Can anyone provide any guidance towards figuring out what is causing this issue? As always, thanks for any assistance you can provide....

 

I think your guess is a reasonable guess, likely either the sensor end wires or the harness end wires are 'disturbed' This could be as simple as coolant intrusion causing a bit of a short which would go away when things dry.

If that doesn't happen, you'll need access to the connector. Then you could do pinpoint tests to figure out which issue it is (p 932 of the 2003 Workshop manual). I, personally, might borrow a hairdryer from my daughter and apply high heat and wind for a bit to the wires on the sensor end of the connector first. Or see if an 'Italian Tuneup' would make things right. But if it's actually an open circuit, may or may not be repairable.

 

Thanks Dale. I spoke with Wayne a few minutes ago and he believes that because I did not think to unplug the other end of the oxygen sensor wiring harness from wherever it plugs into, I probably snapped one or more of the aged wires in the harness when I unscrewed the oxygen sensor from its mounting hole (and in the process twisted those wires considerably). That could very well be because I had to turn it at least 15 or 20 rotations in order to remove it and those very small-diameter wires are now more than 15.5 years old....

So the big question now is where exactly does the other end of the wiring harness plug into its electrical connector, and how do I locate it and hopefully reach it with my hands? Does anyone know?

And the secondary question is what is the correct part number for a new Bank 1 Upstream oxygen sensor with harness (if in fact that is what I will need for the repair)?

 

Can't help with location, but upper sensor appears to be C2P8810 for you according to Cary Jag, Rock Auto, and various random people on ebay...

 

Thanks Dale. What about Denso 2349029 (C2S51801) at rockauto? Its wiring harness length is reported as 17.72 inches.

Your Denso 2349125 (C2P8810) at rockauto reports a wiring harness length of just 11.89 inches. I believe that is too short.

Any way to nail this down for sure?

 

Jon, here is a start on the location of the senor plugs. RD made it sound like all of them are together.
I'll do some more in the morning in the search.

https://www.jaguarforums.com/forum/x...-p1647-104872/

 

Not to be facetious, but find the end... I assume you can see more than 12 inches now?

Just as a data point, the same sites appear to mostly think a C2S51801 is a rear for you?

 

Dale,

With the air intake duct assembly back in place so the car can be driven, I'm lucky to be able to see the sensor much less how long its harness is....

I will speak with the parts guys at both Jaguar Greensboro and Jaguar Cary tomorrow morning in an effort to confirm the correct sensor. Given your wizardry with electronic systems and parts, I will not be surprised if you are indeed correct....

 

Wayne,

Thanks for the thread from RaceDiagnostics but if I remember correctly, he has the 4.0 engine. On my 4.2 engine, there is no way a 1-foot-long oxygen sensor wiring harness is going to reach all the way up behind the throttle body....

I think this is going to be one of those cases where information pertaining to this fix on the 4.0 is not going to help me....

 

Jon, just to be clear on the sensor ID, I did a search on SNG and they have the upper as C2P16392 and shockingly a Jaguar Dealer price on the OEM part.
Still looking.
This Denso was at Advance Part # 234-4951, with over 18 inch lead. The one at SNG looks to be the shorter version and fits both sides, now we are back to the guessing game of who's right.
Several parts places don't even acknowledge the XK before 2015, started to feel like the step child.

 

Yep, it is indeed frustrating trying to nail down the correct part. I hope the two Jaguar dealership parts departments that I will be speaking with tomorrow are consistent (and correct)....

I wish the Magic Parts Fairy would just come down the chimney tonight with the correct one....

 

Jon, RD's car is the 4.2.

The connectors are all in a row located on a metal bracket that sits on top of the bellhousing below the throttle body - above where the octopus runs across.

JEPC give the Jaguar part # as C2N3717, although I'd hate to think what the cost would be (showing out of stock).

It could be that the HO2s heater has coincidentally decided to go open-circuit, but I'd agree with the others and check out the wiring first.

 

Michael,

Thanks for the clarification that RaceDiagnostics indeed has a 4.2 car. But I still do not understand how a 12-inch-long wiring harness or even a 17-inch-long wiring harness can reach that area...

 

I'll nip out and check - mine's obviously 4.0 but I don't think there's much location difference...

 

Bulkhead connector end to sensor connector end direct is around 8". Cable length is 12" on my car.

Appreciate we're not comparing exactly like-for-like, although 17" does seem a tad on the long side. Could that be for the post-cat O2S? I don't have those so I can't check.

 

Thanks for having a close look on your car, Michael. I appreciate the efforts to assist....

 

Did the Sensor 1, Bank 1 about 2 months. (2003 4.2L) After removing the air intake tube, I was was able to locate the connector on the brkt. behind the TB. The Gray connector (upper) is for #1 and the Black Con. is for #2 (lower). The black one is on end nearest you, with the gray one hid behind it. Driver's side connectors are rumored to be near but have not seen them to date. Pull fwd at top slightly and pry up on the connector to get it to release from brkt. Once loose from brkt. remove a locking plastic pin and then SQUEEZE the connector in indicated spots, it will eventually release. May want to tie a string to the connector and pull it out so you can route the new one in same area. I suspect someone had moved my wiring so I routed it where it would not rub or touch anything hot like exhaust. Also, found that a Toyota-Lexus has similar 02 connectors (male & female) so a salvage yard should have adequate supply of connectors if you damage one. Have a GREAT HOLIDAY SEASON Everyone.

 

Great info indeed! Thanks for chiming in....

And the $64,000 question is . . . . . . What is the part number of your new sensor (assuming it is a Denso)?

 

Kelly (kstevusa) just sent me an e-mail confirming that he installed a Denso 2349029 sensor (also known as C2S51801) purchased from Amazon. Mystery finally solved. Thanks Kelly....

 

Just ordered a Denso 2349029 sensor from amazon.com. $92.43 with sales tax and free shipping. It will supposedly be delivered next Sunday, December 27th. We shall see....