I have a 94 S-10 Vortec V-6 with 123,000 on it.
Recently, it seems to have developed a rough idle, similar to a miss. When running down the highway it runs smoother than silk.
I have put in new plugs, plug wires, distributor cap, and rotor. There are no error codes. Passed PA's emission testing with flying colors(running cleaner than last year's test).
Any ideas on possible causes?
Thanks in advance.
Ron