exhaust leak

hi,
i have 2001 lincoln town car signature series and my exhaust is leaking and i got it checked and mechanic told me its the gasket that combines the catalytic converter and muffler pipe. my gas mileage had dropped to abt 12- 13 m/g from like 17- 18.i have changed my plugs and coil packs as well. can it damage my catalytic converters too and sometimes the car is loosing power when driving at highway then comes back. anybody can help pls???

Hello, & yes on the converter.how many miles??hows the car run??does the ck engine lamp come on??leak should be repaired & could effect the way the car drives, gas mileage.Let us no!!!

A good muffler shop can check the back pressure on a catalytic converter.

Too high of pressure means it is plugged.

Symptoms:
Loss of power,Too Hot,and will damage engine.

I have seen them plugged + blown out .

No pressure could mean that it is Blown.

If you tap on a CAT and it sounds empty,the BRICK is gone!

The down stream oxygen sensor will show some damage + parts of the Cat will rattle in
your exhaust system.

Symptoms: This will through a code,and give poor fuel + emmissions.