What are the symptons of a catalytic converter going bad?

What does a vechicle do when the catalytic converter is bad? Does it run, etc?|||Hard starting, won't start at all, rough idling, poor acceleration and gas mileage.|||As far as the chemical reaction slowing or quiting, there really is no way of knowing except by the computer messing it doesn't store enough oxygen to oxidize the HCs and, CO, and NOx emissions.


The substrate can also deteriorate, causing it to rattle.


They can plug up if an ignition misfire allowing fuel to coat the substrate is left go too long, and even in THAT case they sometimes can be cleaned up using the MOTORVAC carbon-cleaning system-believe me, I've tried all the different cleaners/chemicals/ procedures and have the best luck with the MOTORVAC system. That being said, if you are having a catalytic converter efficiency issue, its still a 50/50 shot at he MOTORVAC system cleaning the cat enough to bring it back to life. Find a shop that utilizes the Motorvac system, and expect to pay anywhere from 75-175 clams for the service.Worth the risk in my professional opinion, and some shops, knowing you are trying to save a converter, will give you part of that back towards them replacing the cat if it doesn't work|||Power loss, fuel economy is getting really bad, characteristic "rotten egg" smell from the exhaust, check engine light on showing bad O虏 sensors, exhaust over heating.





Any or all of the above points to the CC.|||Nothing. Its really not supposed to ever go bad really. Its just a part of the exhaust with precious metals that change the composition of the exhaust gasses. Carbon monoxide into carbon dioxide.|||More important is how not to make it go bad. Keeping the vehicle tuned up is very important. Every 30,000 miles or sooner. Poor combustion from delaying a tuneup causes more unburned gases to flow through the catalytic converter, causing it to overheat, and, in my car's case, melt and completely block the exhaust. Car stops!|||Normally if plugged up they will run sluggish at higher speeds and make a whooshing noise out the tail pipe at high rpms Sometimes they still function ok but rattle inside.|||stalling, rough idling, rotten egg smell.