Trouble Code - PO431 warm up catalyst efficiency - below threshold

[davidhowson]

all ok with the air pump, but the sponge filter was really grim so gave it a wash and let it dry before refitting and testing tonight.
Pipes all look good too.
Will have to see how she runs for the next few days, if may just have been a odd italian thing!

 

[Tas4200coupe]

Mine’s come back! Where’s the sponge filter you’re referring to? I might try the same job.

 

[Gp79]

It's on the secondary air pump intake, passenger side in the engine bay.

The system is only there to lean the exhaust gas on a cold (rich) start up to reduce emissions, if you get the fault when the engine is at normal operating temperature i would think it is something else, lambda sensor or cat maybe?