[Qwk69buick]

My wife's 07 300 AWD started idling rough and threw a bunch of codes, so I decided to pull the upper intake. It was nasty inside

The airflow sensor on top of the intake was also pretty gummy. I used carb cleaner, engine degreaser and several different brushes to completely clean the butterfly valves, the shaft between the ports especially and as far inside as could be reached, then blew it all out with the pressure washer.

the flaps now move freely. I also cleaned the throttle body, PCV valve, cleaned and lubricated the intake runner control motors.

I used my scope, the intake valves looked great, but I couldn't see the injectors, so out they came (it was also throwing an intermittent #3 injector code)

They are now clean as new, I also cleaned the injector bores with my shotgun brush, after stuffing a towel into the intake ports to keep gunk from falling in, then vacuumed everything out.

I will put a light coating of grease on the O rings so it should slip right into the cleaned bores without any force.

I am also replacing the plugs obviously since you have to remove the intake to do so, which I am sure made sense to someone. The EGR tube was hand tightened by the head with no gasket and loose in the intake, that won't be a problem going forward

Was still pulling 17 inches of vacuum which is surprising.So how much would all this cost, I have heard dealers just replace the upper intake rather than cleaning it.