1996 Ford Thunderbird

Engine problem
1996 Ford Thunderbird V8 Two Wheel Drive Automatic 135000 miles

I have a 96 Ford T-bird with a V8. The check engine light starts flashing when I give it gas. I hooked it up to a diagnostic machine and it gave me the following codes: P1120 - TPS Censor out of range low, PO430 - Catalyst System efficiency below threshhold, and PO304 - Cylinder 4 misfire detected.
Unfortunately no-one at the auto shop had a book to tell me what these codes mean. Are these codes bad? It would be a real help if someone could help me figure out what these codes mean and what do I have to do to fix it.
January 11, 2008.

Catalyst efficency code deals with your catalytic converter, and chances are it is going bad, but it could be caused by the missfire on the cylinder #4, I would check into that first. If that doesnt clear it up then you will have to replace the catalytic converter.

The TPS out of range is more then likely a bad TPS or one that is not adjusted, it helps controll injector pulse and spark also. Coudl be causing hte missfire.

Jan 11, 2008.