First of all, EGR worries-- I take it you've got the 1.6 engine, where the EGR valve sits at the side of the air filter box. If it's the 1.4 engine, the EGR is at the back of the cylinder head and such a pain to get to that, by the time you've removed everything to get to it, you may as well fit a new one! Is the engine management light permanently on or is it just a 'stored' code that has been read? If you do a bit of stop-start driving, such as crawling in a long queue of traffic, and the milage is such that the EGR pipework is a bit carboned up, then the management light may come on with fault code saying 'EGR Performance'. After a run, the fault light will go out, but the code will have been stored. That doesn't affect the car's performance as the sensors have simply noticed that the 'EGR Performance' is a couple of percent off-spec. If the garage didn't clear the fault code when they first saw it, it will still be there after you've blanked-off the EGR!

A good plan would be to buy your own fault code reader. You can get one for about forty quid from your local car-parts shop. I've got a Sealey one which shows the code and it's description, and it allows you to clear the code.

If the EGR sticks closed, then the engine will run perfectly. If the EGR sticks open, then you'll be running with a rich mixture and laying smoke.

The fault as described sounds (to me) like fuel starvation. I'd go for fitting a new fuel filter first.

Hope this helps, and I hope that what I've written is correct.. I'll soon have some of the more technical posters correcting me....