HELLO EVERYONE

ABOUT A MONTH AGO MY CHECK ENGINE LIGHT CAME ON AND UPON CODE RETRIEVING IT SAID I HAD TROUBLE WITH THE CATALYTIC CONVERTER,WHICH BY THE WAY HAVE THE TICKING SYNDROME.I CLEARED THE CODE SINCE THE TRUCK RAN WELL.BUT SINCE THE DAY BEFORE YESTERDAY I HAVE BEEN HAVING SOME TROUBLE STARTING IT.IT STARTS WITH LOW REVS AND SOMETIMES STALLS .AFTER IT STARTS IT RUNS WELL.IT IS A 98 DISCO WITH 118000 MILES.WHERE SHOULD I START TO DIAGNOSE THE PROBLEM SINCE NO CHECK ENGINE LIGHT IS ON?AS ALWAYS THANK YOU.

 

Idle control valve maybe? Somebody will have a better idea.

 

Good place to start. Clean your throttle body and stepper motor.

 

How many miles on your current plugs and wires, have you changed the 02's yet.
Whatever is wrong, you should fix that first and then replace both cats.