Secondary air injection system

Asked by May 11, 2018 at 10:33 PM about the 2001 Audi A4 1.8T quattro Sedan AWD

Question type: Maintenance & Repair

I bought a 2001 Audi A4 Quattro 1.8l that had
modifications done to it which involved deleting
most of the secondary air injection system. The
check engine light stays on and I get the p0412
secondary air injection switching valve circuit A
code. How do I go about fixing it?

1 Answer


you could always jsut go to the dealer and ask them to print out a diagram for you. You can also get the haynes manuel. Anouther thing is find anotuher car like yours and look at it and how its setup. If the guy took it off and it runs fine tho i would jsut leave it. other wise if it bugs you find a junk yard and take out the parts your missing.

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