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THS 3" Decat install Write up

Discussion in 'A4/S4 forum(B5 Chassis)' started by billybravo, Nov 21, 2008.

  1. billybravo
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    billybravo MODERATOR Moderator

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  2. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    Interesting. I didnt remove that heatshield on the driveshaft when i did my cat, but no amount of pulling/twisting would get the cat clear of the car. It seemed that the cat would either get wedged between the chassis and turbo, or against the head.

    Perhaps with that shield out the way it would have come out some more, but i ended pushing the cat back down as far as i could in the engine bay, and cutting the front pipe with the grinder. Then pulling the cat and stub of the downpipe out the top and the rest out from under the car.

    I guess your way would be better if your planning on keeping the front pipe intact though!
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  3. billybravo
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    billybravo MODERATOR Moderator

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    if you have ramps then pulling the cat from under the car is the best idea but like most ppl dont then i would recomend doing the way ive done it no need for grinders.
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  4. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    i dont think the cat would fit out the bottom? it wouldnt go thru the gap between the bulkhead/subframe/gearbox?
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  5. ALPINE
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    ALPINE Yes its diesel, now cry u lost

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    My De-cat arrived today! :)
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  6. Siena
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    Siena Active Member

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    So when you guys bust your CATS, do you have spare ones to fit, come MOT time?

    Especially if you take an angle grinder to it? :ninja:
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  7. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    Well i took the grinder to the front pipe, not the cat, as i was changing it anyway as the flexi was shot.

    Plus i was replacing a (unbeknown to me) gutted cat with a real one for the MOT. The amount of hassle it caused i really wouldn't think it was worth swapping it out every year come MOT, even though it did give a bit more performance with the gutted cat on there.

    What i'd probably do, is get a universal 100 or 200 cell cat, and fit it underneath the car using some of audis finest dual clamps. Those things are awesome and would make swapping the cat out and back a piece of cake! Would justt need to have a section of pipe the same length as the cat to swap it over. Or just keep the 100cell item in there and be a hippy ;)
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  8. Ronniebiggs
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    Ronniebiggs Member

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    Did you have any probs with the ECU?

    I have been warned off from the decat pipe as people have said you get all sorts of lights coming on the dash due to the sensors for the CAT?

    Also Billy Bravo, what make is your airfilter, where did you get it from? Looks good

    Andy
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  9. billybravo
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    billybravo MODERATOR Moderator

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    this link is now broken but i will try and find the doc again on my files and get it on my new server
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