CEL codes 0491 & 0492 = SAI ?

[brock911]

I had the dealer perform a scan due to CEL. The codes came back 0491 & 0492 = SAI. My question is what are the likely reasons for the SAI issue and ballpark cost to repair?

I'm of the understanding that the Secondary Air Injection system is designed to inject air into the exhaust intake which helps the car run rich on start-up to heat up the catalytic converter a little quicker?

This doesn't affect performance, or at least it hasn't yet, however, how long can it be driven this way before it gets worse if at all?

Opinions appreciated,
Thanks,
Mike

[JFP in PA]

The secondary air injection is a system, not a device. As such, there are several components (air pump, air change over valve, vacuum switching valve, etc.) that can stick or fail, causing the pump to not activate, and you would get these codes. It could be something small or the pump itself maybe bad, but without further diagnostics, everything would be speculation.

Over time, a malfunctioning SAI can annoy the cats, which gets very expensive as the main cats are more than $2K US each. This is also an emissions issue, so the car may have inspection problems as well.

[FPB111]

Drive it for a long time or until state inspection time.
The SAI system injects air into the exhaust upstream of the cats to get them to "light" sooner. It is a pollution control help.
If your pump has stopped working you might be able to take it apart and clean the carbon out of the disks that make up the air pump end of it. If the motor has failed you can buy a new Porsche branded Bosch SAI pump from Porsche for ~$1000 or get the same Bosch pump from a supplier for ~$300.

03 2003 Porsche 911 Air Pump - Air Intake - Bosch, Genuine - *********

[brock911]

Originally Posted by FPB111

Drive it for a long time or until state inspection time.
The SAI system injects air into the exhaust upstream of the cats to get them to "light" sooner. It is a pollution control help.
If your pump has stopped working you might be able to take it apart and clean the carbon out of the disks that make up the air pump end of it. If the motor has failed you can buy a new Porsche branded Bosch SAI pump from Porsche for ~$1000 or get the same Bosch pump from a supplier for ~$300.

03 2003 Porsche 911 Air Pump - Air Intake - Bosch, Genuine - *********

I appreciate the input, thank you FPB111 for the info and link. I'm not that mechanically inclined or I would tackle this. Any idea what it will cost to identify the actual cause?

Or should I simply have a tech replace the pump regardless and tend to the other possible culprits at the same time just to be sure of addressing the problem?

Trying to get an idea of the worst case scenario re cost, the dealer service tech indicated its a matter of time to identify the actual cause and this could get somewhat expensive. I'd rather have some knowledge of what the possibilities are?

Any additional opinions?
Thanks,
Mike

[FPB111]

Mike,
As JFP stated it could be any of the components in the SAI system.

Often it is carbon build up in the pump "vanes" that could be cleaned during a DIY pump disassembly/rebuild. (Probably not if you are not mechanical)

If you hear/heard a sound like an angry high pitched vacuum or a saw cutting through thin sheet metal for a minute or so after a cold start it is likely the pump itself.

The pump lives next to your left knee when you are standing looking into the engine bay. It is held in with 3 screws a connector and a hose. All are very easy to access. So a pump change is not a hard DIY.
On a cold start a dealer tech should be able to diagnose a bad SAI component in a few minutes with the PIWIS computer.