Catalytic Converter

[justinius7]

I'll crawl under the car and check for exhaust leaks, try that and see what i can find.

The car is registerd in Wa. State, so I will continue to "mail order" my tags, as emission testing is not mandatory if you live in rural area's of washington state.

Is it possible that i have an oxygen sensor or some sensor that is not working properly, if so is there a way to check for fault codes, or does that have to be done at a shop.

Also, if I buy a 2.5 inch magnaflow cat and have it installed will it make a huge diff?

thanks!