I do believe that I have a clogged Cat. I have all of the symptoms associated with this. I have been thinking about installing magnaflow high flow cats for some time now. This is pretty much the perfect time to. I was wondering which ones to get?

For anyone wondering what my symptoms are: Low (500 rpm) idle
It jumps/jerks
Sulfur smell coming from exhaust
Decreased fuel econ
Restricted performance on the dash, with CEL (wont let me get above 3k rpms)
And it is a little sluggish

Thanks in advance!

 

It should also throw a code when the cats are bad.

 

Joe, doesn't sound like bad cats (still could be). What motor (V6 or V8)? Snoop around for vaccume leaks, loose air box cover, etc. Retrieve codes. Bad O2 sensor(s)?

 

Im getting bank 1 & 2 lean.

 

Ok, you have a vaccume leak. Coming from: cracked vaccume lines and/or where they connect or at origin, loose airbox lid, intake manifold leak, IMRC gaskets, etc. You still haven't indicated wether you have a V6 or V8? If V6, then our moderator, Rick (Joycs'Jag), is the expert on V6 vaccume leaks, etc.

 

Ahh, sorry, its a V8. I drive a '04 S-Type R. I think I have found where the leak is. Would a vaccuume leak cause all of the above symptoms?

 

Yes, easily.

 

Well I sure am glad that I used the wrong billing information last night when ordering the cats from amazon. I am pretty positive that I have found the hose that is leaking, would wrapping it in electrical tape suffice?
Also, I went to change my fuel filter last night and discovered 2 stripped lug nuts. Would it be worth my time to take it to a tire shop to see if they can get it off with an impact wrench? Or should I just go ahead and get some vice grip pliers?

Edit: I just got my car back from the mechanic, on friday, after blowing a head gasket. When I picked it up it showed a CEL and restricted performance. He told me that it would take a few days for the computers to reset. He cleared the codes and I got the CEL and restricted performance back that night. I drove it all weekend, hoping to magically reset these computers. Monday coming home from work I started to smell the sulfur, when I got to a stop light I felt it jerking, noticed the low idle, and the sluggish performance. I checked the MPG's and I had averaged 13.4 since friday. When I got home I popped the hood and heard it hissing. I took it to the mechanic yesterday and he told me that it was most likely the cats. I showed him the hissing sound (apparent leak) and he sprayed pretty much my whole engine with ether and got no results. Since it didnt suck any ether in and respond he told me that it wasn't the problem. I don't think I will be going back to him.

 

Depending on where the leak is, it might work for a temporary fix. Eventually the heat from the engine will soften the tape and your leak will reappear. I had a cracked EGR vac line and taped it until I could get a new one. It would last for a day or two, then it would leak again. Good luck.

 

The leak is in the hose that runs to the throttle body(I believe), it runs under where the intake runs to the block. It goes to or from the right side (by the windshield) to the front of the engine and around to the left side.

 

the only hoses to the throttle body other than the air intake are the coolant lines not vacuum. I think you need a differant mechanic. Not getting that vac leak fixed is killing your cats. Replacing them before you get the vacuum leak fixed will kill new ones. "electrical tape"???? Fix it correctly
POST PICS OF WHAT YOURE TALKING ABOUT

 

This is where the leak is. Well thats what I assume since as soon as the mechanic moved it, the sound quieted down about 75%.

 

This is where the leak is. Well thats what I assume since as soon as the mechanic moved it, the sound quieted down about 75%.

 

Sorry that it posted that twice. I will get it fixed properly, I just need something to hold me over for the rest of the week.

 

Joe, that's the crankcase ventilation hose running from intake manifold on drivers side to the front of motor, inserting on the PCV valve on passenger side cam cover. It's the largest vaccume line. It may be cracked or the intake manifold gasket is leaking. If there's an intake manifold gasket leak, moving the hose over the intake will give the impression that the hissing subsided as it covers the area of intake manifold gasket leak. Remove the hose and test it for leaks. On the STR, the charge coolers are in the way of properly using spraying ether to test for intake manifold leaks. A smoke machine will do best to detect most leaks. You mentioned that this car was fresh back from a blown head gasket. I'm betting the douche bag mechanic messed up vaccume lines upon reassembly, or worse...improper sealing of the intake manifold, etc?

 

If that tube is leaking it will give you rough running and lean engine. That produces the same crankcase leak as leaving the oil fill cap off. Try that on a good running engine and watch how crappy the idle gets. Not only does the intake have to be tight for proper air to fuel ratios, but so does the crankcase. Dipsticks orings go bad and are big leakers too. Yeah tape is fine till you get the new tube

 

Is this the right part? (but for the 4.2 supercharged) 2003-2008 Jaguar S Type Breather Hose - Air Intake - Genuine, Right 03-08 S Type Breather Hose - 548-01163321 - PartsGeek

I am only seeing one for the 2003 model, does that make a difference?

 

I had the same issue I found that the plastic air intake had a very small crack in it took me a few times looking at it before I found it, was on the bottom. take it off look very hard for it.