Secondary Air Injection Veterans needed

[ddruker]

I just finished refreshing the SAI system on my 2001 Boxster S Tiptronic. I was seeing about once a month OBD code P0410 accompanied by the Check Engine Light, associated with the car sitting for a while, so I assumed I had a slow leak somewhere that was triggering the code after the car sat for a week or more and the vacuum slowly escaped. The code does not occur when I am driving the box more frequently. Like the prior poster, I took the "replace everything" approach since the parts are only about $200 and this project requires a lot of painful/annoying labor.

I replaced all of the plastic lines and rubber fittings with 4mm inside diameter / 9mm outside diameter silicone vacuum hose, 3/16" or 5mm outside diameter brass barbed fittings (one 4-way, one 3-way Y shaped, and a couple of barbed connectors) and about 20 8mm hose clamps, all purchased from Amazon for about $30.00. I used about 5 feet of the silicone hose, I would buy a 10-foot section so you have extra for mistakes.

I also replaced the vacuum accumulator tank $21.00 (993-110-140-03), two of the vacuum switches $17.00 each (7PP-906-270), the one-way check valve $15.00 (964-110-950-02) and the air injection valve $99.00 (997-113-249-90). I would have replaced all three vacuum switches but I only ordered two of them as I am dumb sometimes.

Probably because I have the S with automatic transmission, the following things were different than I've seen discussed in most of the rest of the SAI Threads.

- I had 3 vacuum switches. One controlling the air injection valve, one heading down to the automatic transmission, and one controlling the air intake resonator flap.

- I had a four-way junction attached to the vacuum accumulator, and also a three-way junction attached to the check valve.

- The check valve was plugged directly into the right-hand rubber boot on the air intake resonator.

I accessed everything from above and from the passenger compartment, after removing the alternator. It was VERY tight working underneath the intake manifold - in particular reaching the bolts on the underside of the air injection valve was challenging. A very small ratchet with 10mm socket plus a 10mm wrench did the trick, and I had to remove my gloves and fiddle by hand to get the bolts in from underneath. I also had to remove the intake manifold resonator tube as the lines run underneath it.

The existing air injection valve did not have a gasket installed. I installed a gasket with the new one - the metal gasket is included with the new injection valve.

The system would have been impossible to repair using the existing tubing - after 20 years, the rubber connectors were effectively welded to the hard plastic tubing and to the other various valves and switches, and the hard plastic tubing was super brittle. I broke most of it trying to disconnect the old system, and I was being pretty careful.

The whole project end to end took about six hours, and it was not very fun.