I have a 98 Safari 4.4 Vortec with 225,000 miles on it.

It is running rough with no error codes. It is hitting on all 6 cylinders.

It has a new distributor, cap & rotor.
Bosch Platinum plugs & plug wires are about a year old.

I have a 98 Safari 4.4 Vortec with 225,000 miles on it.

It is running rough with no error codes. It is hitting on all 6 cylinders.

It has a new distributor, cap & rotor.
Bosch Platinum plugs & plug wires are about a year old.

Make sure none of your plug wires are in contact or near contact with the exhaust manifold. Also a good idea to remove the doghouse and check out the engine while idleing at night to check for any errant spark. I stumbled upon a leaking wire this way which had come in contact with the manifold and was throwing an intermident spark into manifold. I wish I had started this way as I would have saved myself alot of time and money. Also alot easier to check vacumn hoses while doghouse is off.

Thanks! :)
I had not thought of looking after dark. I unplugged the wires one at a time while running & got a pronounced miss on all six so whateever it is does not seem to be isolated to a single cylinder.

I have checked for vacuum leaks & not found any.:banghead: