Catalytic Convertor ?

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Jul 13, 2005 | 04:12 PM

DopeA6

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Catalytic Convertor ?

Can a blockage in the cat(s) cause a misfire at idle??

Jul 13, 2005 | 07:52 PM

JWG

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No, misfire means fuel not properly ignited by spark plug . . .

blocked cats will cause exhaust fumes to back-up and choke the engine's breathing---unlikely to cause misfire at idle (low exhaust volume) but not at higher rpms (high exhaust volume).

I would VAGCOM your ECU fault codes first, then start theorizing. It could result from ignition problem (plugs, coils, amps, etc) or air/fuel mixture problem (too lean usually) or carbon deposits pre-igniting or detonating fuel early.

Jul 16, 2005 | 06:10 PM

STASIK_A4

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A Blocked Cat will cause loss of power.... It happened to me Earlier on this week...

Now im running empty cat with out any problems car goes harder and turbo spools up beter and quicker.... keep in mind that we only have 1 O2 senssor...

How ever a Misfire is caused either by poor spark plug, bad ignition lead, bad coil or dirty injector...