My brother has a 97' XJ and his check engine light went on the other day and he said it started to act up on him. Apparently at random when driving he will just lose power and it idle down almost at 0 RPM's and when he presses the gas it won't do much. We went to AutoZone and had them hook up and he printed out all of these engine codes.

My Question to you which codes should I be more worried about and do they have any correlation?

135-O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)

122-Throttle position sensor voltage low

700-The automatic transmission computer or Aisin computer has a problem - ask it what's going on. I don't know.
300-Misfire detected in multiple cylinders.

132-O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)

306-Misfire detected in cylinder #6. O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)

Thank you for any help. I really do appreciate it

 

Kinda looks like his catalytic converter collapsed and is clogging the exhaust. Have him hold onto the exhaust pipe and smack the catalytic converter a couple of times. Chances are he'll hear it rattling.