De cat or not to de cat

[Sluttysmurf]

Been looking on ebay and this popped up..


http://pages.ebay.com/link/?nav=item.view&alt=web&id=321574256107


Not stupid money!

I know its not mot friendly but just got a fresh 12months ticket!


Anyone had much joy with these?

Thanx

Martin

 

[Joe_Murphy21187]

It's doubtful anyone will notice a CAT missing in the engine bay, but depending on how well your engine is running, you could fail on emissions as it's a petrol.

Best way to ensure an MOT pass for a petrol is a sports/high-flow CAT rather than de-CAT.

 

[Gazwould]

Or just swap for your old cat once a year.

 

[Sluttysmurf]

It's doubtful anyone will notice a CAT missing in the engine bay, but depending on how well your engine is running, you could fail on emissions as it's a petrol.

Best way to ensure an MOT pass for a petrol is a sports/high-flow CAT rather than de-CAT.

Yer I'll prob just swap it back over for the mot,


Has anyone got one?
Notice much difference
Power wise or performance?
Thanx

 

[45bvtc]

Some Audi garages offer a pre-MOT so worth checking.

Last September I had a pre-MOT without secondary cats on my 2011 RS3 and then the MOT proper with secondary cats fitted (Audi wouldn't pass the car without the secondary cats fitted): the CO results were 0.02% without and 0.01% with and the pass limit 0.20%

 

[DrStrange]

Im not an expert on this, but from countless hours of reading up on de-catting..i'd say look for a 3'' pipe for maximum airflow.
A decat along with custom exhaust will see HP gain. On some cars the dyno has read 10-15+ HP

 

[jaybv6]

Isn't the exit from the turbo 3inch and not 2.5inch? I believe the cats steps down from 3inch the turbo side to 2.5inch after the cat.

I may be wrong though.

 

[DieselJake]

Fairly sure it's smaller than that, if it's not an S4/RS4 or something heavily modified best bet is having a 3" decat to 3" downpipe.

 

[DrStrange]

Yeah, i think its smaller than that too. 3'' all the way if you can..