Well, seems I got hit with the Restricted Performance light. Hooked up my Code reader and got a Very Small leak in the emissions, time to get the XJS out of the garage, and the VDP in and start tracing it out. Guess this is good opportunity to make a smoke detection can I have seen on Youtube

 

That would be handy to have around. Can you supply a link?

 

Doing a smoke test is always a good idea, but I do not immediately see how a small leak (as you described) can set the light.
There is quite a wide range in emissions before the Engine light will come on (and I am not even sure it will result into a Restricted Performance).
Keep other causes in mind.

 

This is one of many ideas on Youtube. the sidebar has others

 

That's what I intend to do. figure since I have it in the garage, I am going to check over things starting at the front. But I have heard a small EVAP leak can gave affect and give off the yellow/amber warning