Got codes, what should I do first?

[Capricious]

I pulled these last night. Truck runs good until it gets up to operating temp then starts stumbling.

P0470-Exhaust back pressure sensor circuit malfunction.

P0478-Exhaust pressure control valve high input.

P0603-PCM processor keep alive memory (KAM) error.

P0676-Glow plug #6 circuit failure

P1316-Injector circuit/IDM codes detected

P1000- OBD II more driving needed.

Thanks,
Bobby

 

[95_stroker]

That IDM code raises my eyebrows, as does that #6 glow plug. Those are the first two I would look at, prolly the #6 GP first, make sure its not shorting the harness out.

 

[Capricious]

That's the harness thats integrated into the valve cover gasket right?

 

[95_stroker]

Yes, if one of yoru glow plugs went south it may have begun to melt the connectors between the wire harness and he VC gasket.