P0305, fixed, ran fine, then P0305, P0302 and P0306

[Dukester]

97 Expy, 5.4L, 119k miles.

Got a P0305 several weeks ago. Slight miss at idle, as well as uphill or under load. Cruised fine. Replaced the plug and boot and it ran fine for several weeks.

Now a couple of weeks later, P0305 is back and it brought it's friends P0302 and P0306 with it.

Have new COP's on the way but I find it odd that 3 COP's on two banks would go south at the same time.

Thoughts?

Cheers,

Duke

 

[Bedrck47]

I would change all plugs and boots at the same time put some dielectric grease on the wire inside of the boots or new plugs and cops the cops should have new boots with them and again use some dielectric grease on the boot wires

Also check the connectors to the coils make sure contacts are clean and tight and also use some of the same grease on the contacts

 

[docraymund]

If you replaced all coil on plugs and spark plugs and still get a miss, then it's time to check the fuel injectors.