How do you fix codes P0443 and P0305?

Answer 1

J30

I don't know what J30 means, but maybe I can help. P0305 means cylinder 5 misfire detected (cylinder#5 is 2nd one from firewall, driver's side). You must find the cause of the misfire. Check the spark plug, and if crusty/worn replace your plugs (all of them). If it is/looks new, swap the plug wires for 5 and 3 (at the plugs and distributer) and see if p0303 comes up. Replace plug wires if it does. Also inspect cap and rotor, if it's an older durango without electronic ignition. If still misfiring on 5 (or random cylinders), and it's a '98-'99, check for vacuum in the valve covers by placing the palm of your hand over the open oil fill hole while engine is running. If you detect a vacuum, you probably have a bad intake plenum gasket. Verify by pulling the throttle body off of the intake and inspect the inside bottom of the intake manifold for oil. If oil is present, replace the intake plenum gasket. See TSB 09-05-00. A quick Google search will give you the repair procedure.

Also, look up TSB 18-48-98. It concerns the routing of the plug wires, and the most common symptom is P0305.

My chronic P0443 code cleared after I performed the above TSB's on my '99 Durango, although I have no idea how the two could be related.