Jeep issued an emissions recall in late 2006 to update the powertrain control module (PCM) software on certain 1996 - 1998 vehicles. As part of the recall, the catalytic converter will also be inspected for damage and replaced as necessary. To see if your vehicle is included in the recall you can visit the Jeep website (owners' section) that allows owners to input their VIN number and check the recalls on their vehicle.
Car Problem Reports
Jeep Cherokee Emissions Recall Due to Catalytic Converter Failure
Jeep Cherokee Problem
Average Mileage: 164,500 mi (130,000 mi - 199,000 mi)
Took it in to the dealer, did the job for free, and fixed the noise that went with it.
Visitor, 1997 Jeep Cherokee, 199,000 mi
Failed Emissions test. Mechanic is replacing the PCM, a burnt engine coil, and the catalytic converter. $1700 repair job