# Help with P0432 main catalyst below threshold (Bank2)



## rkb74 (Sep 23, 2008)

Hello,
I bought a 1999 Audi A4 2.8 Quattro and the check engine light on and I checked the code it say P0432 Main catalyst below threshold (Bank 2) and I hear a little bit of rattling noise I am kind of new to Audi so can anyone help me with this.
1. Is the oxygen sensor gone bad?? if so should I change all four 
2. Or do I need to replace the catalytic converter if so which one??
Thanks
KB


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## AvantBoy19 (Aug 5, 2005)

*Re: Help with P0432 main catalyst below threshold (rkb74)*

It is the catalytic convertor on the right side. while your at it i would change your Oxygen sensors cuz if your cats are bad then your oxygen sensors are gunna be quick to follow. The rattling is probably the platnum honeycomb inside that has broken down from heat and vibration. http://****************.com/smile/emthup.gif 
good luck


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## AvantBoy19 (Aug 5, 2005)

*Re: Help with P0432 main catalyst below threshold (AvantBoy19)*

Also if you want a good performing cat replacement. Check out magnaflows Hi-flow universal cats. I put 2 on mine and it flows alot better and gives a nicer tune with custom exhaust.


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