e0em9mlc

Ok..so, Im new to the site so, here goes.

So, I 've replaced, the pump, check valve and relay.

I've manually applied vacuum to both Konbi Valves and manually activated the pump and confirmed air flowing from the exhaust at rear of vehicle.

I can hear the pump working at start up and run for approx 90seconds then turn off.

I confirmed the vacuum switch is working by removing vacuum line (when the engine perform a cold start) and felt the vacuum suction.

Everything appears to working however, during the cold start when the secondary air pump is running, I hear what appears to be an exhaust leak or a back pressure noise in the vicinity of the passenger side Kombi valve. Odd thing is this noise goes away after approx 90 seconds when the pump turns off. I can't find any evidence of a leak.

Any Suggestions are welcome.

alx

You have an air leak. Put the car on a lift. Have somebody start the car. Look/ listen from underneath. It is usually the air injection pipe fitting into the exhaust/ cat.

e0em9mlc

Alx: I'm thinking and air leak as well but, I can't find any evidence of it. I'm not familiar with the design of the system (how secondary air is delivered to the CAT). What I can see and know is the Kombi valve bolts directly to the head. I can see the passageway inside the head but, beyond that I have no idea how the air is delivered to the CAT. I assumed it's mixed inside the head and delivered through the exhaust manifold. thanks...