Just wanted to post this info in case anyone else has this problem. I was told by several that this means I need to replace my catalytic converters. My 2000 S-type 3.0 ran fine, except, at red lights it would die occasionally. Also it would idle rough at times. I had checked all the vacuum lines and elbows, or so I thought. There are two rubber breather elbows at the back of the engine. One is about the size of your pinky finger, and the other is about thumb size. The tough one to get to is the thumb size since it is under the fuel injector rail. I do not believe you can get to it without removing the plastic intake manifold and injector rail. If someone knows a trick, please share. Also, the problem I had is the thumb sized elbow looked good from the top, but the bottom had collapsed and had a hole in it which was not visible from the top. I could here a vacuum leak, but until I reach under this elbow and felt the hole, I was perplexed as to where it was coming from. I assumed that it was bad intake gaskets, and was about to put the car back together when I noticed the collapsed elbow. Thank goodness I found it, or I would have wasted the time and the cost of new intake gaskets, because I would have had to go back into the intake later. If you have this problem/symptom, plan to replace your plugs, and at least the passenger side coils while your are in there, since you can only get to them with the intake out of the way. I hope this helps - $8 Jaguar part saved me over $800 in cat.converters!

mtfife