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Had the Milltek cat bypass pipes fitted earlier today.





Best £100 ive spent on a mod in a long time! It sounds stock on start-up and until "S" is pressed and then its bloody awesome. Cant believe how could this engine can sound.

I'll use the go-pro tomorrow and get a video of the sound.

Heres a test video i did yesterday using the Go-pro but it gives you an idea of the before sound.

http://youtu.be/ElFYfphMBOk


All at legal speeds so the reg doesnt matter. First go at using the camera and imovie to edit so excuse the music and titles etc.

Told you, what difference there is in it!

Best mod ever isn't it for that price?

nshort10 wrote:Told you, what difference there is in it!

Best mod ever isn't it for that price?

It was after i read your thread and you said it was stock sound at idle and in normal mode, This is what i wanted and not it being an animal all the time.

I let the lad that fit it drive off up the road so i'd get to hear it from the outside, Awesome mod

Hmmmm . . . this has me thinking that I should see if they do it for the S4. I look forward to your next clip.

I'm just back in from a night out with the other half and coming home through the quite streets I always seem to hit "S", drop it down a few gears and boot it. Always put a grin on my face!

But my neighbours must hate me haha!

I'm thinking after my chip I will get the cat back system also but I'm not 100% sure if I should or shouldn't!

I'm not sure whether the Millteks too much, It sounds a little farty on some clips.

I'd like to hear one in the flesh before i decided but i think id be dissapointed having done the cats. If your exhaust was totally stock then it'd maybe be a big difference.

any problems with warranty with this fitted?

Preston audi weren't happy to work on mine with this fitted / do warranty work

did sound a lot better though, they even commented about that in the service department!!

It's illegal though isn't it? I assume you are ok until the car is 3 years old and needs an MOT?

Yep, you'd definitely need them off for MOT.

MikeFish wrote:It's illegal though isn't it? I assume you are ok until the car is 3 years old and needs an MOT?

Nope, decats themselves are not illegal !

The car must still pass the emissions test, I've had cars pass decatted before. If it needs to be replaced in 3 years time the garage I use will happily swap it for the test for around £20 so it's certainly no drama.

This shouldn't void a warranty, they'd need to prove it was the cause of the problem.

It's totally stock sounding at idle in normal mode, you'd never know inside the car even when driving. If the Audi garage decide they want to test it in "S" at full chat then the issue won't be the decat, it'll be what justification have you for driving my car like that!

For the sake of a 20 minute swap and around £20 cost to swap I can decide depending on what works needing to be done under warranty whether its changed or not.

So how does the caat bypass work in real life? surely you would need a remap to get the best out of it muck like gutting precats and also to avoid sensor errors and maximise its performance?

P_G wrote:So how does the caat bypass work in real life? surely you would need a remap to get the best out of it muck like gutting precats and also to avoid sensor errors and maximise its performance?

The secondary cat is post lambda probe, guess its more like deleting a centre resonator.

Pity these things aren't readily available for other cars

You could go to any exhaust fabricators (powerflow, Longlife etc) and they will knock one up of you, it is just a straight through pipe isn't it?

But on an RS4 there are lambdas on the primary and seconday cats so a bypass wouldn't work unless you mapped out the sensors.