RPM's dipping below idle speed

[Hornung418]

Hornung, I haven't yet inspected the back of my manifold but am pretty sure my SAP valve does NOT have a vacuum line attached. Other E46 threads have talked about this line but I just don't see it, and I still have stock exhaust manifolds. My SAP assembly has two electrical connections and my theory is the check valve is just a one way valve that lets the SAP push air into the exhaust manifold but doesn't let exhaust gasses escape and melt the SAP when the SAP is not pumping in air.

Or... maybe the valve is electrically activated?

Looking at the ECS Tuning catalog for E46 330 cars, it appears their SAP kit for cars up to 02/2003 includes vacuum lines and the SAP kit for cars from 03/2003 forward does not include vacuum lines.

There's a hard line that runs from the metal valve on the head to the back of the block. It's totally there if you have the SAP.

[Hornung418]

[LivesNearCostco]

OK I didn't look for a metal hard line or for the switch thing to be in the back near the manifold ports. I'll look for these next time I'm in there.

[Hornung418]

OK I didn't look for a metal hard line or for the switch thing to be in the back near the manifold ports. I'll look for these next time I'm in there.

It's possible that the line is bundled in with the O2 sensor wires that run along the VCG.