So my 2002 Audi TT Quattro is throwing a CEL PO420 code. Checked for exhaust leaks and found nothing. Pulled the Cat o2 out and want to test it with a multimeter to see if its still good. Does anyone have the numbers or have a link to a repair manual pdf?

Thanks.

 

No repair manual PDF out there. Most folks buy the Bentley service manual.
Should be able to find it on amazon or ebay for about $60.

cheers.

 

Hey thanks for the advice, I needed to get this done today so I ended up further looking into the problem and I found I had a bad exhaust gasket in the upper flange so I replaced the gasket and bolted it up better. There was a really tough bolt to get to and to also loosen up and re-tighten on the backside. I erased the code and it hasnt returned, yet...