I have been living with this Restricted Performance notification off and on for a few years with no remedy still.

Yesterday, after having the Coil in #4 cylinder replaced again...after leaving the repair shop in less than three blocks the Restricted Performance notification came on again. The car seemed to be running rough as sometimes happens when the notification appears. After awhile the notification disappears and all is well...usually the check engine light does not come on.
This morning on a cold start, even before I got completely backed out of my garage, the Restricted Performance again came on. This time the Check Engine Light was blinking and now is on solid although the Restricted Performance note went away. I took it out on the highway and it performed well.

Please is there someone on this forum that has had similar experiences with this problem and can you tell me what more I can do to get to the bottom of this problem.

I love my XK8, but this is getting me down.

PS I dont know if this is related but I sometimes get a display that the Anti Lock Brake system is inoperative....but this also goes away on its own.

I will try and get a new code since the Check Engine Light came on.

 

Bruce - there could be any number of things causing the issue - take to any Advance Auto or Auto Zone and get the codes read and post the codes here so techs can best determine what may be causing your problem


ABS would not cause restricted performance and could be a dirty sensor or the ABS module - first thing I would do would be to clean the 4 sensors

 

Here's a list of codes that show, mostly misfire (030x)
But certainly get the codes read.

 

Had the codes read again and here is the result:

P0304 Cylinder # 4 too many misfires
P1313
P0354

This coil was just replaced again last week.
The spark plugs were all replaced about 6000 miles ago.

Car has been running perfect the last two times out on the road. But just dont know when the Restricted Performance will strike again.

Sure would like to get it resolved.

My mechanic says it could be the PCM

What should I do next?

 

P0354 is Ignition Coil 4 Primary to secondary circuit malfunction - causes:

ECM to ignition module primary circuit: open circuit, short circuit to ground, high resistance
Ignition module ground circuit: open circuit, high resistance
Ignition module / coil failure


P1313 - misfire rate catalyst damage A bank causes:

cylinder compression low
Worn camshaft / broken valve spring(s)
Fuel delivery pressure (low / high)
Fuel injector(s) blocked / leaking
Fuel injector(s) continuously open
Fuel contamination
Fuel injector circuit fault(s) (Injector DTCs also flagged)
Spark plug failure / fouled / incorrect gap
ECM to ignition module primary circuit fault(s) (Cylinder misfire detected DTC also flagged)
Ignition module ground circuit: open circuit, high resistance
Ignition module / coil failure

I'd look at cabling to coil or injector to start

here is a link to DTC's

http://jagrepair.com/images/AutoRepa..._2001_OBD2.pdf

 

Maybe a new but bad coil or the wrong coil was replaced (easily done).

 

I would SWAP the coil and plug into 2 different locations, and then see what misfire occurs, if it's still 4 then wire / pcm / injector.

 

Thanks to all who have offered some insight to my problem.