Just found this useful info. Clears up what the secondary air pump does, and what activates it. Also confirms in my mind that it is infact totally pointless! Especially if you've removed your cat!!

Anyway, hope someone finds it interesting...

'Secondary air injection system

Operation

Air is injected downstream of the exhaust valves by the secondary air system for up to 100 seconds after a cold start (+5°C…+33°C coolant temperature). This enriches the exhaust gas with oxygen, initiates a post-combustion and thus shortens the heating-up phase of the catalytic converter. Actuation is performed by the Motronic control unit –J220- through the secondary air pump relay –J299- to the secondary air injection valve –N112- (changeover valve) and combination valve. In addition, after each subsequent engine start (up to an engine temperature of max. 96°C), the secondary air system is switched on in the idle speed range for 10 seconds and checked by the self-diagnostics. The lambda control must be active for this purpose.'

That probably explains why they all run like a bag of S##t when they are cold.

Indeed. Just had the hole in the cylinder head for the secondary air on mine capped off

Mine still cuts in even after cold start (Like 10 mins after driving?)

Performance is NOT affected but strange why it does this :confused:

mie doesnt work and brings up code with vag com. desnt really bother me though.

Indeed. Just had the hole in the cylinder head for the secondary air on mine capped off

Ahh I was having a look at it today and thought about that!

How do you get round the error code popping up? Or does the pump still run, and just pump air to atmosphere?

Would be interested to hear about your setup.

I'm a hater of non-essential items that reduce reliablity...

i was quoted around £200 iirc to get a replacement for it.

Ahh I was having a look at it today and thought about that!

How do you get round the error code popping up? Or does the pump still run, and just pump air to atmosphere?

Would be interested to hear about your setup.

I'm a hater of non-essential items that reduce reliablity...

I'm cheating, not running std management so dont have anything to control it anyhow.

Oooh nice. What ECU are you running, if you don't mind me asking?

I want a Motec M400....

Emerald V3