Pre-cat removal 2.5 & Exhaust options

[S4_dan]

Just bought a fully gutted pre-cat for a massive sum of £1.70! £6 postage so not all bad

Why not gut my own? Well I'd rather keep one in good shape in case of future problems/issues/MOT's etc etc. And at £1.70!!!!

So, I know access is easy at the turbo end but the other end? Is it access from under car or do I need to drop the full system to swap it out?

I'm hoping it may alleviate the lack of torque/power issue on my 2.5.



I know there are two more cats a bit further along and will look at having them removed in the future.

Am I right in saying that after the cats is one silencer where the pipes split and lead to the rear boxes on each side?

If so, has anyone removed the middle box and left the two rear boxes

or

Leave the middle box and removed the rear boxes?

Cheers,

Dan

 

[adamss24]

It does not make that much effect to be honest ! I still run mine...but no main cats though !

 

[MooLard]

I guess the engine management system limits any big differences but in the past on other cars I've generally noticed the turbo spools up / kicks in a little sooner.

 

[S4_dan]

It does not make that much effect to be honest ! I still run mine...but no main cats though !

What did you replace the main cats with Chris? Something homemade or a purchased pipe?

 

[S4_dan]

I guess the engine management system limits any big differences but in the past on other cars I've generally noticed the turbo spools up / kicks in a little sooner.

Fingers crossed it might help my no torque issue below 2000 rpm then.

 

[AlexGSi2000]

I have no cats in mine, passes its MOT every time.
I have a full stainless system, with two silencers either side on the rear tail-pipes.

 

[S4_dan]

I have no cats in mine, passes its MOT every time.
I have a full stainless system, with two silencers either side on the rear tail-pipes.

Do you still have the pre cat in?

What does your sound like then? Any videos?

 

[AlexGSi2000]

Do you still have the pre cat in?

What does your sound like then? Any videos?

Pre-cat pipe is still there but the innards have been removed.

It sounds really good to be fair, I have a few more recent videos which I can upload, this one is fairly old - it sounds a little different now due to the engine running properly. (a lot of turbo blow-off noise in this, its a lot less now!)

 

[VagCabby]

I gutted my pre cat and main cat last week on the 2.5tdi 163. The diffence is amazing car is alot more responsive and suprisingly smokes less!

I did the pre cat first and it made ****** all difference so I did the main cat a day later and that made the difference.

to remove the pre cat the easiest way is

1. Unbolt the 3 bolts holding the pre cat to the turbo and loosen off the pre cat from the turbo

2. Get under the car and remove the drive shaft guard above your nsf drive shaft

3. Unbolt the front exhaust mount (held on by two bolts) this allows the access to a pita bolt!

4. Rach up from under the car and unbolt the 3 bolts secueing the pre cat to the exhaust

5. Pull the pre cat out from the top of the engine bay.

once you have done it once it takes about 10 mins to remove

 

[S4_dan]

Good info there VagCabby.

Cheers, I'll have a go as soon as I get chance. Do you only have one main cat on your system? Mine has two I'm led to believe. Not looked under the car at the front yet.

Cheers.

 

[S4_dan]

Pre-cat pipe is still there but the innards have been removed.

It sounds really good to be fair, I have a few more recent videos which I can upload, this one is fairly old - it sounds a little different now due to the engine running properly. (a lot of turbo blow-off noise in this, its a lot less now!)

Sounds good. What causes the blow off noise then? Did you turbo whistle a little before doing the exhaust?

Dan

 

[quattrojames]

Or, buy my system with it's lovely shiny stainless tips and gut away to your hearts content, and then keep your system perfect to replace when you sell it :icon_thumright:

 

[S4_dan]

Is that a standard system James?

 

[adamss24]

What did you replace the main cats with Chris? Something homemade or a purchased pipe?

It was a custom made 3" downpipe splitting into 2x 2.25" twin exhaust branches.

 

[S4_dan]

Looks sweet! Does she sound good?

 

[quattrojames]

Is that a standard system James?

Yep.

 

[adamss24]

Looks sweet! Does she sound good?

If you're talking about mine (!), it sounds lovely on idle- nice burble on tick-over and gets bit throaty as the revs increase but no drone on long motorway runs ! One of the best exhausts i've heard in a long time...

 

[VagCabby]

Good info there VagCabby.

Cheers, I'll have a go as soon as I get chance. Do you only have one main cat on your system? Mine has two I'm led to believe. Not looked under the car at the front yet.

Cheers.

no worries

mine goes from the pre cat into a very big main cat the a long single pipe into a large silencer which splits into 2 and goes to 2 back boxes I think yours will split after the pre cat due to being a quattro, mine is FWD

 

[S4_dan]

Yep.

If it was a custom system I may have been tempted James. Looking for a bit of growling under throttle plus free flow in the hope I could restore my no torque issue before 2k rpm. At least that's what I keep telling myself. Lol

 

[quattrojames]

No problem, I'll be ebaying my standard system soon and just wondered if it was any use for you to gut the cats etc off the car whilst still keeping your original set up in one piece.