Engine Performance problem
1999 Mazda b3000 6 cyl Front Wheel Drive Automatic 93000 miles
Recently my truck started running a little rough. At idle would jossle a little. I also couldn't pick up speed to pass another vehicle or enter a highway. Engine light came on and would backfire when trying to pick up speed. Took to a mechanic who told me there were 2 (not 1) faulty wires going to spark plugs. In essence I was running on 4 cylinders. Replaced them and the plugs. Replaced EGR(?) Sensor. Today after all this was done the truck runs worse than before. Seems like its missing or not firing, or backfiring still. From a stop it is very sluggish to pick up speed (wasn't like that before) and it won't go over 45 mph. Talked to mechanic and he is now thinking catalytic converter is bad (explanation that it was due to all the backfiring and is now clogged) Sound right? Or is a new mechanic in my future?