I have a a ongoing restricted performance intermittent fault problem on a 2006 SE D S Type. Based on the diagnostics I have had the port deactivation valve replaced, the fault was still there the next day. I was then told by the Jaguar Dealer it was now showing the EGR valve to be faulty. Tried blanking the EGR valves but this made the problem worse. Finally had a Jaguar specialist in Kent replace the valve (30% cheaper than main dealer). Fault still there but diagnostics showing no engine management fault!!! Light comes on after about 10 minutes, typically down hill when the engine is not under load. If I stop and restart, the car will run fine for the rest of the journey, has anyone experienced anything like this?

Have you changed the fuel filter on your car recently?

I have the same car and am experiencing the same problems I need to change EGR valve and replace the port deactivation valves but I found that the main cause of the limp home mode was because of the fuel filter needing changeing as well.

How did you change the port deactivation valves and how difficult are they? I have brought the replacement kit.

The first 'port of call' for me when working on these cars is to the check the battery - under load - as if the battery is on it's way out (not bûggered, just fading) you will get all sorts of strange electrical bugs,triggering reduced performance.

Dave

Even truer for the diesel than any other S-Type. And even more so in the current weather.