i just recently changed the spark plugs, wires, rotor & dist cap... truck ran like a champ! then i noticed while the vehicle sat in traffic a ggod while, the lights & dash lights would dim then restore once the truck was driven a distance.so i changedthe altenator, prrrrr like a kitten.
so now two days later, the truck is taking longer to start, seems like not enough pst from fuel pump or not enough spark!? took it to get diagnostics- mechanic said the computer was bad!!! said to replace to see if that would fix the hesitation start! could that be? it also feels & sounds like a pillow is over the flow master cause it doesn't make the same hollow noise anymore... i took it to a muffler shop they suggested removing the cat, i did, truck still hestitated to start, put the cat back on.... what could it be?

 

To start with, if you have a fuel pressure gauge, check the pressure. Second, pull a plug wire off a plug, insert a rubber handled screwdriver blade into the end, and hold the exposed blade about 1/4 inch from an engine ground (I wear a leather glove while doing this). If you have spark, it will show. Also, what knid of muffler shop can't tell if a cat is plugged or not?