My STi 08 impreza has the engine malfunction light on together with other lights which shuts down the cruise control and engine power options. My garage says it's the combi? air pump and valves that need replacing and they are expensive. Can anyone explain what these parts do? Thanks.

 

On first Initial cold start up for 30 seconds the secondary air pump operates to push fresh air direct in to the combi valves which in turn open up and inject the air into the exhaust Gas stream which then in turn causes a chemical reaction in the catalytic converter to heat up quicker in order to get the emissions down to an acceptable level. Basically this system was fitted so the engine could meet current Euro 5 regulations.

My opinion is its utter ****, I had mine switched off by my selected mapper.

I doubt that all the system will need to be replaced, usually the valves can seize internally & they are a real pain to change especially the one under the inlet manifold.

 

Thanks Rob, they quoted £1200 for fixing it which is a lot considering it doesn't actually do much.

 

By the sounds of it. They've priced a pump & 2 combo valves inc fitting for that amount, I'd ask a mapper to go into the ECU and erase the codes permenantly so it doesn't effect anything.

 

Thanks Rob. Are you saying these parts can be removed altogether or ignored and the engine, cruise control etc reset to normal. Would that affect the emissions when it comes to the MOT? Neil

 

We frequently delete these parts, re programming the ECU to suit.
We do have various parts of these systems about the place if you'd like to stick with it. £1200 is ridiculous.

 

Good news! The fault has cleared itself - everything now working normally. Must be the recent warm weather last Sunday? Thanks for your advice. If it happens again I will be in touch. Neil