what is this thing, and would it cause my 5th and 6th ports to not open up? my car is still stumbling at 3800 i've checked the injectors, i checked the cpu ground and the ports are free but idk if there opening up or not and that little plug is broken.

 

as u say it is the ACV, ive done away w/ the whold 5th/ 6th port system and i dont wanna get into a contraversy about it. Can u just replace the plug to it? have u place grease on the actuators and taken it for a drive to insure the actuators are moving properly. U could also do an electric port operation.

 

hmm i didnt think about the grease thing i'll have to try that. but no i cant i need to get a new one it umm melted in an engine fire i had thanks to a 99C o-ring caused 100$+ worth of damage

 

It's the port air solenoid valve. It opens to increase the amount of secondary air injected into the exhasut ports to reduce emissions.

No. The S4 auxiliary ports are opened by exhaust backpressure. It's a purely mechanical system.

 

Just somewhat relevant about the Port Air Solenoid. I had the operation of this valve backwards for years. The car has a twenty thousand mile switch, which after twenty thousand miles puts a gnd on a ECU pin. When that happens the Port Air Solenoid is activated. I've had this *** backwards for years and tought that after twenty thousand miles it did just the opposite.....deactivated. Live and learn. The RTEK2.0 made me aware of that.