One problem related to catalytic convertor has been reported for the 1997 Nissan Nissan Truck. The most recently reported issues are listed below.
Multiple sensors that control the fuel injection and emission control systems have failed prematurely. The air charge temp sensor, bpt valve, egr valve, catalitic converter, and throttle position sensor have failed. All of the parts except the converted have been replaced - the dealer refuses to replace it, claiming it is ok. A different Nissan dealer I had to stop at while on a trip told me it is not ok, that it is plugging up. Response from regal Nissan dealer has been "too bad, it's out of warranty".