Well that was a huge PIA. Anyone, who says this is a couple hour job, apparently doesn't have my car. Got back from work travel and tackled the final nut. In the end, I came in from the front, with a swivel adapter, extension, and breaker bar. That was to get the initial "crack". Then I came in from behind, with the torque adapter and got it loosened up. Then returned to the front to back it the rest of the way off with a regular ratchet.





Chewed the nut up pretty bad. Going to replace all four, for good measure.



For anyone else doing this -- I ended up removing the heat shield for the starter cable, and the cable itself. Was worth the effort to get the little bit of extra working room.

With the last nut off, I got to fight with the clamps that hold the down pipe to the mid pipe. The ridge in the downpipe means you have to open the clamp and the end of the mid pipe up pretty well, to get the ridge out. It does look like the clamps have some sort of lightweight metal gasket inside that helps with sealing. The drivers side shed a bit when I pulled the downpipe out. Reminded me of bearing confetti. You can see it inside the actual clamp in the picture below.


I'll probably go ahead and replace them. I'm not spending "just for the hell of it", but I also promised the car that I wouldn't skimp on anything when working on it.

With that, the downpipes are out.




On the subject of not skimping. Should I replace the O2 sensors while I have everything apart? I know they have a history of failing. I also know that JLR extended the warranty on them to a ridiculous period of time. I also know that JLR is probably not going to honor that, if they fail, since the car has an aftermarket exhaust and tune. The sensors are original -- I'm lucky in that I have the entire service history of this car. So I'm weighing the approx $400 for all four, versus Murphy failing one of them shortly after I get everything put back together. No it's not terribly hard to replace them in the car. No, none of them are bad right now. Yes, it's easier to do now. Yes, they are technically a wear item. Yes, they will eventually need to be replaced.

 

I’ve seen many references on the forum over time about sourcing the equivalent Bosch O2 sensors from other sources for significantly less than getting them from Jaguar. Something to consider just in case you are not aware, and it might make it even more feasible and worth the effort of replacing them now while you are in there etc…

 

Oh, definitely. I spent some time this morning cross referencing the Bosch part numbers. No way am I paying $275 per sensor. If I am doing JLR parts, I'll go through landleaping.com, or another online reseller unless I have to have it "now". Even then, it's about 50/50 whether the local dealership will have it in stock. For something like the O2 sensors, original manufacturer would be preferred, if possible -- Bosch in this case. My first stop for most car things is Rock Auto and then I'll move up the expense ladder as I feel appropriate. As an example (for folks new to this, not necessarily @DMeister ) -- I need to replace the rear toe adjustment links. Online JLR (landleaping.com) is about $175. Rock Auto has cheap replacements ($20-30) but they are aftermarket and depending on your view of certain manufacturers (MOOG, Dorman, etc), you may not want them near your car. OEM was likely made by Lemforder and I can get those from FCP Euro for $90 each, with free shipping. So that's what is on the way.

 

When I did my downpipes back in 2020, I never replaced the O2 sensors and they have been working fine ever since. I see no reason to replace them if you are not having an issue. They are mostly accessible and easy to replace in the future if needed. I would recommend however using some good copper thread sealant to avoid these from being seized in the future. Just a good, inexpensive measure to take.

 

Anti-seize was a given. Taking out the existing ones took way more force than expected, given the torque specs. They weren't seized, but it was a good hint for reinstall. That and the fact that the new ones advertise coming with anti-seize on them. Not sure how much I would trust that though.

I did go ahead and order the four rear ones. Though thinking about it now, I suppose I should have asked if the mid sensors are still needed. I know a tune is necessary to keep the CEL from coming on, when putting in the downpipes. This makes sense as the mid sensor moves from mid catalyst to pre-catalyst and now would seem to be a duplicate of the sensors in at the output of the exhaust headers. Wondering if the VAP tune deletes the mid sensor altogether, or just changes the expected values to match what is seen pre-cat. My downpipes came with a pair of bolt/plugs in them, one side its in the mid sensor position and one its in the rear sensor position. That setup wouldn't make sense to me, but the option to delete the mid, now pre-cat, sensor would.

 

I remember how fun these were to install Good news is they sound great and are still going strong with no issues or O2 issues either so far👌

 

Glad to see you still posting Rock! Had not seen you on the forum for a while. I thought we lost you and you had purchased a different car and moved on.
Your instruction and how-to threads are still about the best out there!
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For everyone following along, the exhaust work is effectively on hold at the moment. I've got multiple different things underway with the car at the moment and I've been busy tearing into the front of the car. There are a number of things that will block installation of the new exhaust. The downpipes won't go back in until I'm far enough along with the cooling system work that I can close up the drains in the block. The muffler won't go back in until I can get the tip replaced -- local place that does stainless welding is closed for the holidays, and I need to replace the rear tie rods. Those should be arriving this weekend. Exhaust has to come out to do the tie rods, so it won't go back in until they are done.

Replacement tip came in, and its a thing of beauty.

 

I've started putting the exhaust back together and I have a question for those that have done this before.

Do I tighten the downpipe studs down to the shoulder? You can see, in the picture below, that the stud is all the way down, with the bracket sitting on the shoulder.




All the documents, that I have found, list the torque spec for those nuts as 40nm. That doesn't come anywhere close to seating the shoulder down against the bracket on the new exhaust. It would seem to me, that over time, the flares would stretch some and the whole thing would get loose -- unless the stud shoulders are up against the brackets and torqued, so that it's not the exhaust pipe that's providing the counter force. However, it will take a fair amount of wrenching, and quite a bit of force to flair the exhaust pipe and seat the studs on their shoulders.

@scott@VelocityAP any guidance? Or insight from doing your own?

Anyone else?

 

@GerbilEngineer It is a ball and socket type of connection. It won't seat all the way down like you are thinking. It is designed that way.

 

Yeah, I just wasn't sure if what I was seeing was expected or not. Others will nod when I say "the shop manuals tell you what to do, but not how or other details in most cases". Add on top of that the fact that this is 3rd party and I figured it was better to ask both you guys, and the collective wisdom, rather than make an expensive mistake. None of the threads or other guides I have read have mentioned it one way or another.

 

I took the old mid pipe clamps off. Got the angle grinder out to cut the connecting strap and clean up the remnants.




The old clamps are pretty beat up.


The clamps themselves aren't cheap, but I decided that give the cost of the new exhaust, I wasn't going to skimp out on $100 worth of clamps so I'm putting new ones in.

Before I started putting in the downpipes, I changed out the O2 sensors in the headers. Yeah, probably uneeded, but I have no desire to try and get to those, with the downpipes in. Plus, I'm putting in new sensors in the downpipes. Barring unexpected failures, I should never have to touch these again.





I haven't taken pictures yet, but the down pipes are installed and the header connection and center clamps are tightened enough that they stay in position, but nothing is torqued down yet.

 

Here are the O2 sensor part numbers I ended up with -- all have been confirmed to be correct fit.

upstream (2x): Bosch 0258027164 (Jaguar # C2D24756)
left mid: Bosch 02580300DD (Jaguar # LR091883)
right mid: Bosch 02580300DB (Jaguar # T2R7732)
left downstream: Bosch 025803004F ( Jaguar # C2D54165)
right downstream: Bosch 02580300CR (Jaguar # T2H5129)

The Jaguar part numbers are the current active part number, as best as I could determine.

 

Yesterday, I powered up the car for the first time in a month, so I could dump the ECU and send it off to VAP for tuning. I power the car with a 30 amp power supply connected to the power terminals in the engine bay. Power supply was set to 13.5V. General load was about 8 amps with the driver door open. I did not connect the battery. Worked fine.

Don't do what I did.

Yes, the car powered up and I was able to dump the ECU without any problems. However... when the car is powered up, it does several things. For example, when it detects a key it pressurizes the low pressure fuel feed by running the fuel pump for around 10 seconds. When you turn the car on, it cycles the AC/heater and runs the aux coolant pump for a few seconds. This is fine except when the car is the state mine is in, with the charge are cooler and supercharger removed and all the hoses disconnected. The garage still smells a bit like gas. I spent a fair amount of time cleaning coolant out of various nooks and crannies in the valley. Luckily, I had all the intakes plugged with rags. I only had to blow a bit of coolant out of one of them.

 

This evening was a big step. The new exhaust is in place.

Tips were wrapped while I wrestled it in place, with the help of my wife. Having someone, that can lift on the tips, will help you get the angle and alignment, with the mid pipe, correct.




It is in place and the hangers are torqued down. However, the mid pipe clamps are still loose. Part of the reason for getting the muffler in was to help set the alignment of the mid pipe so I can torque down everything from the downpipe/header connection, all the way back. The other reason was to clear the floor of the garage, to pull the wife's Telluride back in before we get several inches of snow/sleet/ice dumped on us this weekend, along with 10F temps.







I will need to pick up some vacuum line. The little bit from the valve to the elbow, on the stock exhaust, is not near long enough to connect to the VAP valve actuators.

 

Yesterday morning, before the garage got too cold, I finished up the exhaust. Well, finished except for the two vacuum lines. All the bolts are torqued. All the O2 sensors plugged in. Starter is reconnected and the protective metal is back in place. Heat shield for the rear O2 sensor connectors is in place. I didn't put any of the splash guards back in place yet. That will get done once its been run and the cooling system checked for leaks.





The left resonator is a bit lower than the right, it's not just the pictures that make it look that way. It's about as far up as it can go, while leaving clearance to the heat shield. I could lower the right one slightly, to make them match, but it's not a big enough deal for me to care to unbolt everything.

I didn't toss the original, damaged exhaust tip. I printed up a stand for it, and added an inset for the VAP badge while I was at it.

 

Hi,

sorry if I have a stupid question regarding the installation of the downpipes. Is there a thread in one of the flages of the new pipes to reinstall the original studs? Or do you have to replace it on one side with a screw and a new nut?

 

We provide two new studs with the kit that attaches to the new downpipes.

 

Scott beat me to it. Downpipes come with studs. My personal advice would be to go ahead and order a set of nuts though. Mine front facing ones got chewed up pretty good when taking them off.

 

What a cool idea. Looks great