Secondary Air Injection Issue

[Dan Warner]

I'm working on a 2000 Boxster S, last week the CEL came on with DTC P 0410 and P 1411.

I found a very slight vacuum leak in the reservoir under the intake manifold and replaced it along with the electric change-over valve and the air change-over valve. (and all the vacuum lines)

After a day or two the light came back on with the same two DTC's.

I actuated the blower and electric change-over valve with Durametric, both seemed to work fine.

I place a vacuum gauge (we'll call it the first gauge) in the line before the electric change-over valve another ( we'll call it the second gauge) between the electric change-over valve and the air change-over valve to confirm the air change-over was getting vacuum on cold starts, to my surprise it was NOT!

I started the car to build up vacuum in the reservoir (confirmed with the 1st gauge), turned off the engine and re-actuated the electric valve with Durametric, and it DID pass vacuum to the air valve (confirmed with the second gauge)

So why is the ECU is turning on the blower with out actuating the change-over valve?

Keeping in mind that everything works fine when actuated individually with Durametric.

[flyingpenguin]

Subscribed!

[Loren]

Sounds like the relay or the change-over valve.

[Jager]

Using your Durametric capture the voltage levels of your O2 sensors in front of the catalytic converters, during a cold start with the Secondary Air Pump running (you will have to be quick to start the motor and start the Durametric program), the voltage should be very low and flat-line. If the voltage is not flat line what kind of sine wave/pattern do you have (copy screen and post the graph so we can see)?

Edited April 5, 2014 by Jager