Micheal;
Which hose are you talking about? UFO is the big black disc?
I only see one on the passenger side of the STR?


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This guy. Replacing the hose might be the best bet.

 

Ah ... not PVC hose (PVC - a kind of plastic), but PCV hose (PCV - positive crankcase ventilation).

Well, any hose making a vacuum leak is gonna cause grief...

 

Ah yes sorry about that. I am not sure exactly where the leak was, but once I put in a new hose it fixed it.

 

No worries, very easy to hit letters in the wrong order!

 

Ok. So ive got the STR back from the workshop. Drivers side catalyst repalced, it had only started to collapse but replaced anyway. I havent had chance to test the fuel trims yet, but its done nothing for the symptoms (still intermittently down on power), so a bit gutted really.

During the works, the technician had a good look around and noted that the EGR pipe had failed at some point & had a botched repair. The Manifold>EGR pipe is half missing where it goes into the manifold. The exhaust manifold has been plugged up (botched) with a random O2 sensor not even from a jag, and the remainder of the pipe going into the EGR is just hanging there sucking up air unmetred air. He seemed pretty confident that this was causing the trouble, but suggested running it "as is" to avoid costly repair.

I guess if the EGR still works is sucking in unmetred air instead of exhaust gasses. Would this cause my STR to run so poorly and give me messed up fuel trims/reduced power? No error codes at all - is this good or bad?

I've done some reading on the EGR valve on the forums, Im aware of how much of a swine these are, but happy to be getting closer to the problem. Thanks for all the suggestions so far, I'll hunt around my engine bay tomorrow to see if there's anything else adding to the problem.

 

Any source at all of unmetered air is bad news on any modern car. The closed loop control relies on sensors, actuators and proper vacuum sealing.

 

Good job I think you found it!

Just get in there and change the EGR valve, get a new EGR tube and it sounds like some hoses are messed up too?

The O2 sensor is cross threaded or blocked off?

I don't mean to be harsh but I don't see how the guy could say just run with it???

The damn car won't run right and keeps losing power unpredictably.
Not to mention the check engine light is on!
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Getting to the back of that PCV tube where it connects near the throttlebody is damn near impossible... I think you have to remove the throttlebody in order to get to it, $40 hose from jaguar though...

 

After a long, long Saga, im getting closer to resolving this!

Got the car back after getting the above EGR pipe "fixed", but the issue still remained and several months of painful & heartbreaking ownership endured.

After spending a further £3500 replacing every gasket/seal/vac pipe that can be replaced (along with plugs, and several days worth of diagnostics and stripping things back and 3 catalytic converters), we found that the the first garage I took the car to "Fix" the EGR pipe diddnt bother using a Gasket where the pipe connected to engine. Possibly a mixture of EGR pipe and other vaccume leaks, but angry isnt the word.... (Stay Clear of Karl Fisher Autos in Cannock, UK). I am however happy to have that issue is now mostly resolved. (Thanks to Elite and performance Jaguar, Derby!)

Car still isnt running perfect, however after replacing a coil pack after getting a Cylinder 5 misfire has made it run better than ever before. The car has its bark back and 95% of its speed, Im about to order another 7 coils, and hopefully my STR will be running as Jaguar intended soon

I will post the long list of gaskets and replacement parts for all to see in the next few days, in the hope it can assist someone in the future.