Pre Cat removal

[vRS_Pagey]

moderately tempted to have a go at this myself today, however I'm a bit concerned about breaking the turbo bolts........

[Bogwoppit]

My car has just sailed through another MOT emissions test without the Pre-Cat.  

If you are DIYing this mod here are a few tips:
- Make sure everthing is cold.
- Spray some WD40 on the turbo nuts and the 1st Lamda sensor.
- Remove the 1st Lambda sensor before undoing the turbo nuts.
- Ramps or axle stands or car lift needed.
- New turbo nuts and the Gasket come to about £10, you might as well change them.

On a different note how much is Cat material worth at a scrappy as I have 2 Cats worth lying around somewhere?

[vRS_Pagey]

My car has just sailed through another MOT emissions test without the Pre-Cat. 

If you are DIYing this mod here are a few tips:
- Make sure everthing is cold.
- Spray some WD40 on the turbo nuts and the 1st Lamda sensor.
- Remove the 1st Lambda sensor before undoing the turbo nuts.
- Ramps or axle stands or car lift needed.
- New turbo nuts and the Gasket come to about £10, you might as well change them.

On a different note how much is Cat material worth at a scrappy as I have 2 Cats worth lying around somewhere?

Good info Bogster.......

Regarding value of the cat material, it will depend what car its from, BMW and Mercedes use far more precious metals in their CATs, tbh though I'm not sure a scrappy would be interested in the raw material, but no harm in asking.

[mortygttdi]

Pagey if both your vrs and golf are diesels they don't have turbo bolts its just a clamp on the turbo to DP

Darren

[vRS_Pagey]

Pagey if both your vrs and golf are diesels they don't have turbo bolts its just a clamp on the turbo to DP

Darren

The Golf is a soot chucker, but the vRS is a 240bhp stage 1 petrol powered hearse.........

[mortygttdi]

Pagey if both your vrs and golf are diesels they don't have turbo bolts its just a clamp on the turbo to DP

Darren

The Golf is a soot chucker, but the vRS is a 240bhp stage 1 petrol powered hearse.........

Thats different then good luck with the studs mate

Darren

[JMP]

I just finished mine, intake is still off so I didnt drive it yet. Hopefully its all ok 

It was a bitch to do since I couldnt raise the car very high. So crawling under the car and trying to manouver around took me over 3 hours. If you can get car on a real lifter this is quite easy task.

The turbo nuts came out easily but I had problems with the clamp that attaches the downpipe to catback. The other bolt was so rusted that I couldnt get it off. So I had to cut it and replace with new ones. I reused all other bolts & nuts and also the turbo seal as I didnt have a new one. Hope its still ok. I didnt remove the 2nd lambda during the operation as it wasnt really necessary.

[vRS_Pagey]

I just finished mine, intake is still off so I didnt drive it yet. Hopefully its all ok 

It was a bitch to do since I couldnt raise the car very high. So crawling under the car and trying to manouver around took me over 3 hours. If you can get car on a real lifter this is quite easy task.

The turbo nuts came out easily but I had problems with the clamp that attaches the downpipe to catback. The other bolt was so rusted that I couldnt get it off. So I had to cut it and replace with new ones. I reused all other bolts & nuts and also the turbo seal as I didnt have a new one. Hope its still ok. I didnt remove the 2nd lambda during the operation as it wasnt really necessary.

Nice work fella, look forward to hearing how you find it................how high did you get the car, and did you use axle stands or ramps?

Regarding the O2 sensors, could these not just be unplugged leaving the sensors bolted in to the down pipe?

[JMP]

Nice work fella, look forward to hearing how you find it................how high did you get the car, and did you use axle stands or ramps?

Regarding the O2 sensors, could these not just be unplugged leaving the sensors bolted in to the down pipe?

I used axle stands on the front, so not very high. To remove the downpipe of the catback you really had to go pretty far back which was a bit problematic.

Well its easy enough to remove the first lambda. I would take it out because when you start smashing the cat out, it will most likely gather a lot of dust/debris. And I didnt see where the connector for 2nd lambda was, so I just left it in. It had enough wire to be able to work on the dp.

[JMP]

I drove the car today and did about ten 3rd gear 80-120kmh pulls with 10Hz GPS + race chrono in my E7. Previously I have been hitting about 3.4s (best 3.36s). Now with decat average went down to 3.2s (best 3.16s). I did have different fuel then last time, I have now 98 and previous runs were with V-power so numbers look good. 0.2s might not sound like a lot but it does take a lot of power to get that down. There is clearly more power now.

The exhaust sound didnt change much. Change was hardly noticeable.. Lets see if I notice it more in daily driving. Car does seem to be reacting quicker now to gas pedal presses and breaks 2nd gear traction very easily.

I will be installing S3 cooler + oettinger turbo outlet kit next, hopefully I can get the 80-120kmh time under 3s when these are finished.

[vRS_Pagey]

Good results there, all academic for me now as I have secured a deal on a miltek dp/sports cat! 

[johnhol78]

I did mine a while ago though I'm confused about the Turbo Bolts?

I literally took out the inlet bolts......just behind the actual engine....

When this was off the pre cat was right inside.

Are these the bolts you're talking about?

Also is removing the pre cat anywhere near a new downpipe for Stage 2? What's the differences? Thinking of having the Cat removed and straight pipe put in which can be swapped at MOT time. Would this substitute a full Milltek for example?

[vRS_Pagey]

I did mine a while ago though I'm confused about the Turbo Bolts?

I literally took out the inlet bolts......just behind the actual engine....

When this was off the pre cat was right inside.

Are these the bolts you're talking about?

Also is removing the pre cat anywhere near a new downpipe for Stage 2? What's the differences? Thinking of having the Cat removed and straight pipe put in which can be swapped at MOT time. Would this substitute a full Milltek for example?

If you remove the OE Cat in favour of a straight pipe (so decatting it) you will achieve the same as fitting a Milltek or similar down pipe, perhaps the performance will be slightly less due to the diameter of OE pipe which iirc is 60mm vs 70mm on the milly and 75mm on a pipewerx.  You will need stage 2 software though and it will through up a CEL (stage 2 will sort this).

[56OctyVRS]

I have done this on my Octy VRS and had Shark tweak my Stage 1 map over the weekend.  I also fitted the SFS boost hoses and will be fitting a K&N Typhoon intake soon I got for a very reasonable price from a fellow forum member.  Once done I will post up the results of the dyno run on the 17th October at Shark.  With just the tweaked map, pre cat and sfs hoses the car really flies.  It is effortless when accelerating and I can easily return 45 mpg on motorway runs. 

[Tfsi_Mike]

Is the SFS hose the same part as the Neuspeed ones? What's your thought on it?