the converter is blocked inside. you have to replace it.
my guess would be a catalytic converter going bad. you can remove the front oxygen sensor and drive it. if the problem goes away then it is probably the catalytic converter. nth njth ///////???????????????????kldghavnivaetahdsngahe
There isn't a converter on a diesel engine.
Depends on what the smell is and what is causing it. Have the catalytic converter tested before you spend the money to replace it. It maybe something else causing this problem.
Yes if it is totally clogged.
Answercatalytic converter efficiency below threshold.http://www.v8sho.com/SHO/TSB0197HO2SServiceTips.htm see web site for sensors locations, copy and paste website in address.....A code PO420, catalytic converter efficiency below threshold, is more likely an indication of a catalytic converter problem, not the sensor. There are different codes that would indicate a sensor problem. However, it is possible that a sensor problem may be the cause of the catalytic converter code appearing. The sensors (newer cars have two or more) measure the differences between exhaust gas before and after the converter(s). Faulty sensors could indicate a faulty converter when it might be the sensors' bad measurements that are the cause. However, a faulty sensor should also generate a bad sensor code. Sometimes another indicator of a bad catalytic converter might be a vibration in the exhaust system near the converter caused by pressure in the converter or a breakdown of the honeycomb material inside the converter.
This light is indicating a emissions problem or failure. The catalytic converter may be operating at low efficiency which is a sign of failure.
It's probably a problem with your catalytic converter.
Depends on what the problem is or what code was set.
Either the thermostat was not the problem, or you put it in backwards.
My brothers 2003 Monte Carlo had this problem, was a plugged catalytic converter.
po421 is catalytic converter problem rear bank
Depending on what kind of "whirring" sound you are referring to, it can either be your catalytic converter or some problem with the exhaust system. Most likely the catalytic converter if its what I'm thinking of.