I posted a week or so ago about rough idol and surging up and down when driving. Like stated I have replaced coil, air mass sensor and pcv valve. It idols better but still jumps and surges when gas is applied. It know has a popping sound like a tin can from the exhaust. Could it possibly be the catalytic converter stopped up. I do have this code after replacing coil p303 and 304 cylinder 3&4 misfire as well as code B1302 accessory delay relay coil circuit fault. Thanks for info you guys can offer. Coop

 

WHen was the last time plugs n wires were replaced?

 

They have not been changed

 

You haven't changed your plugs in 20 years and your confused why your truck is running rough and misfiring?

 

Are you sure the plug wires are fully inserted into the coil? and onto the spark plugs, Not looks like it or I think so, Are you sure?

Have you checked the plug wires for proper resistance with an ohm meter to make sure they are any good.

A set of plugs and wires is where I would start.

 

They have been changed but not since this started happening. It has been about 50,000 miles.

 

crappy Bosch plug wires ive had crap out in 25K. Id say replace wires and pull every plug out and inspect/regap/reapply antisieze

you can get it runnign smooth at idle and lightly mist with an old windex bottle water on the plug wires individually and see if it starts misfiring.