Secondary Air Pump - What Does It Do?

[developer]

Mine was replaced today after MB determined it wasn't functioning.

The car seems to idle better and drive more smoothly.

So - what does it do?

 

[LTD]

It makes your car idle better and drive more smoothly.

 

[developer]

It makes your car idle better and drive more smoothly.

Funny thing is, the service guy said it would help prevent the hesitation..

What foo king hesitation ?

 

[renault12ts]

It injects air into the exhaust system to improve emissions...I think.

 

[LTD]

Funny thing is, the service guy said it would help prevent the hesitation..

What foo king hesitation ?

The gap between filling stations or tyre shops

 

[developer]

It injects air into the exhaust system to improve emissions...I think.

I think you're right (pair of Joe experts we are), but I thought it was a cold start jobbie only - it's smoother throughout, including when up to temp.