So we bought a used 2008 Dodge Durango from a local car lot. The check engine light has been on since we purchased it. The car lot said that they would fix whatever the problem is. It was recently discovered that someone has opened the catalytic converters and gutted them then welded them back shut before we purchased the car, and that is why the check engine light is on. The car lot is trying to tell me that if they replace the converters with new ones the car will run worse. Is this true?

 

No. It is not true. The car lot is liable now if they inspected it and passed it. They are trying to get out of spending the money to make the vehicle legal.