987 Secondary Air Injection

[mbertram]

05 Boxster S MIL came on and codes are P0491 and P0492 indicating insufficient airflow from the secondary air injection system for both banks. The CEL came on while driving and the engine was hot. I was not driving aggressively at the time.

I have not found anything on the internet for 987s (There is a lot for 986s) and the system looks different from the 986.

I cleared the codes and they did not reappear upon restart (yet...)

Is there only one pump that injects air into both banks? What is the most likely cause?

Thanks for any suggestions.

[gizmofixer]

i have the same problem on my 987.2.
mine will repeatedly set the code if i dont baby it till its hot.
from a lot of reading it seems that there is one pump that feeds two checkvalves.
also in the system is a few control solonoids and a bunch of vac hoses.
any one of these items can set the codes.
the older cars seem prone to cracked and broken vac hoses.
i hope someone can post a diagram or a diy showing actual locations for these parts, i cant find any true pictures.........

[jlong]

The high probability fix of the P0491 & P0492 error is to replace the secondary air valve. The valve is prone to fail over time (seize) and not allow the pump to flow air into the exhaust thus causing the P0491 and/or P0492. Use a Durametric or similar on your non-running car, actuate the air pump and check for flow out of the tail pipe. No flow? Blocked secondary air valve.

948 113 203 51 Secondary Air Valve

You must remove the right (pass) side intake and injectors to complete the job so also buy yourself new gaskets for the intake and the injectors for good measure.