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Model specific boards => Golf mk4 => Topic started by: dhorsfall2000 on 27 January 2010, 13:06

Title: secondary air pump
Post by: dhorsfall2000 on 27 January 2010, 13:06
Hi, can anyone tell me what the secondary air pump is for???
Title: Re: secondary air pump
Post by: Waffs1984 on 27 January 2010, 14:00
Take it you have an AUM?

Its basically for warming the cat up to make it last longer and lower emissions on startup IIRC.
Title: Re: secondary air pump
Post by: BaV on 27 January 2010, 16:31
Also does stuff while the car is running. Dont just remove it unless you are going to get it mapped out, car doesn't run the same.
Title: Re: secondary air pump
Post by: LazyLunatic on 27 January 2010, 17:54
if you need a spare i got one :D
Title: Re: secondary air pump
Post by: dubcruiser on 27 January 2010, 21:50
As said it runs for no more than 90 seconds on a cold start to warm the cat up quicker. After that it does nothing! You can remove it but you have to fit a resistor somewhere in the wiring to fool the ECU in thinking it's still there. The is a link on uk-mkivs somewhere I think  :wink:
Title: Re: secondary air pump
Post by: BaV on 27 January 2010, 22:25
As said it runs for no more than 90 seconds on a cold start to warm the cat up quicker. After that it does nothing! You can remove it but you have to fit a resistor somewhere in the wiring to fool the ECU in thinking it's still there. The is a link on uk-mkivs somewhere I think  :wink:

That is rubbish mate, have you ever done it or are you just passing on information you have read on forums?

I removed mine and the car was hesitating on boost and just generally not as fast or smooth.  If you remove it you need to get it mapped out as it clearly does something.  If you are not prepared to get it mapped out then dont do it.  Mine was bad enough that i had to go through the effort of putting it all back on.

On my new engine i am not going to have one as they are prety pointless but they DO need to be mapped out!
Title: Re: secondary air pump
Post by: northeast_gti-t on 27 January 2010, 22:28
and also needs blanking off with an sai delete plate to  :wink:
Title: Re: secondary air pump
Post by: dubcruiser on 29 January 2010, 18:46
As said it runs for no more than 90 seconds on a cold start to warm the cat up quicker. After that it does nothing! You can remove it but you have to fit a resistor somewhere in the wiring to fool the ECU in thinking it's still there. The is a link on uk-mkivs somewhere I think  :wink:

That is rubbish mate, have you ever done it or are you just passing on information you have read on forums?

I removed mine and the car was hesitating on boost and just generally not as fast or smooth.  If you remove it you need to get it mapped out as it clearly does something.  If you are not prepared to get it mapped out then dont do it.  Mine was bad enough that i had to go through the effort of putting it all back on.

On my new engine i am not going to have one as they are prety pointless but they DO need to be mapped out!

I am no expert mate. I still have it on my car and have no intention of taking it off. I did the repair job on it to stop it sounding like Concorde on start up!  :grin: