106 Cat replaced, now dodgy gear changes

There are three possibilities I could think of:

1. Has the mechanic dislodged the heat-shield plate below the cat. It is a thin perforated metal plate. If it is loose, then at certain revs it will vibrate causing the metallic rattling noise.
2. The gear linkage is at the rear of the engine compartment above the exhaust and can easily have been dislodged if the exhaust front pipe was removed.
3. Alternatively the gear l> 106 XN Petrol R Reg

According to my invoice, all that was replaced was the cat and some clamps. The rattling does sound like it's pretty think metal, not a (presumably) thin metal plate.

That sounds pretty likely.

Also likely. I had to drive quite a way with my car sounding like a dragster.

Thanks for taking the time to reply.

Regards, Marcus

Just for your information, the garage had fitted the cat upside down so the curve in the pipe was knocking the gear linkage. Had a local place flip it up the right way for £20 (including a flange ring that was also missed).

MS

I'm in the South East and the garage is in Tamworth (near Birmingham), so all I've been able to do is to send the invoice (with note from garage who re-did the cat saying about the flange ring and upside-down cat) complaining and asking for money.

Fingers crossed. Although it is the principle more than the money I'd say. £20 to sort it is OK, but I would have been fuming if it damaged the gear linkage or cat, as that would be £100 minimum to sort.

MS