# continued problem with rough idle SECONDARY AIR???



## RobWydeven (May 14, 2009)

audi a4 b6 quattro 2.0 2002.......ive had this problem for about 6 months now...When i am idle in neutral my car seems to shake a little bit, but when i give it just the slightest bit of gas it smooths right out....it does not shake at all when driving...the check engine light turns on and stays on for like 2 days and then it seems to shut itself off for like 2 months and continues that cycle....my cousin told me that if it is the secondary air pump , and with the random misfire codes...that would be what would cause this vibration...does this sound right?? i just dont want to pay 350 bucks for a air pump and put it in for nothing....and is it something that has to be done/?/ can it cause damage to my engine??? I figure this might be a common problem...any feedback would be greatly appreciated... thanks!


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## GLS-S4 (Jun 6, 2005)

*Re: continued problem with rough idle SECONDARY AIR??? (RobWydeven)*

Suggest VAG Scan the car and run 01 Engine - Output Test to hear if SAI Pump is working. Clear DTC's, drive car and scan again to see which DTC's return. Repair based on the recurring DTC's.


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## lostroot1 (Oct 16, 2002)

*Re: continued problem with rough idle SECONDARY AIR??? (GLS-S4)*

if it isnt the air pump then more than likely it is the MAF. when the pump comes on it is trying to get more air. and the maf isnt reading it right. but the rough idle will only be when the pump is on. then it should smooth out. you may not get a code for the MAF


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## GLS-S4 (Jun 6, 2005)

*Re: continued problem with rough idle SECONDARY AIR??? (lostroot1)*

The Secondary Air Injection system does not use MAF metered intake air. SAI system is intended for reducing exhaust emissions during engine warm up phase only. SAI pumps fresh ambient air into the exhaust system so that the cats can use the additional oxygen to reduce emissions from ECU intentionally running rich during engine warm up phase.
Your issue is more likely misfires related to ignition system. You need a VAG Scan to know what part(s) to replace. Maybe you just need new plugs? Note that Audi is recalling 3.0L Coilpacks now due to high failure rates causing poor running and CELs.


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## RobWydeven (May 14, 2009)

so i have had my car into an audi tech and he replaced all 6 coils and plugs....still....at times it vibrates a little when in idle...if i give it gas to a little over 1000 rpm it smooths right out.....my check engine light turns on for maby a day every month...and then turns off.....any ideas??? i will be getting vag and cord in the mail soon but im new to the vag com...


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