4200 secondary air system

[jonny 4200gt]

I occassionally get the OBD II light on in my 4200 for the same fault. Had it in to Stratstone Manchester and they diagnosed the secondary air system as the fault. This is apparently a blower that blows warm air onto the cat when the car's starting off. Thye checked it all out and apparenly it all works fine and is a niggly intermittent fault that affects nothing but trips the OBD light.

Anyone experienced this before or know where to look to check things myself ? I'm thinking of going over all connections, unions etc to make sure they're ok.

Cheers

Jonny