Can anyone help me or suggest what may be wrong.

I have a 1.6 Tigra and it has been superb until about three months ago, for some reason the CAT become faulty and fused together and I lost all power, it was replaced and the car went like a rocket better than before, then it lost power again when I went around a sharp round about with a smell of burning, back to the garage and they found the centre box had become blocked with bits from the old broken CAT so it overheated. Fitted a new centre box and it wasnít as fast as before so they replaced the end box and tailpipe just in case more bits of CAT had got blown through the system. But power seems down to me, pick up is not as good.

But every now and then if I take a corner of a round about quickly it will loose power, my foot is hard to the floor and nothing, sometime it will pick up again and sometime it shudders and act like itís going to stallÖ but never does.

The problem I have when it plays up and I take it in to be looked at it doesnít go wrong when they road test it. To me I can feel the over all performance is down but they say itís normal. Never once has the engine management light come on so they have nothing to look at. Itís feels like a 1.4 (I had a 1.4 before so I know how it feels)

Does any one know what it could be and has anyone had this problem.

I donít want to sell the car itís low mileage and is in A1 condition with front and rear spoilers, it did have twin chrome exhaust but they removed that in case that had become damaged/blocked.

It only seems to go wrong if the car is moving sideways quickly or going up or down a steep hill and cornering at the same time, when the problem starts then on straight road it will sometime not accelerate or it kangaroos down the road. And over all feel sluggish.

Any ideas, itís driving me nuts, and I find myself not going in heavy traffic or pulling onto round about, before I could zip across them with out any worryís now it could die at any time.

It does it on a full tank or petrol so I donít think its lack of fuel.

Regards Ray