Do you have part number? May replace as you suggest

Do you have part number? May replace as you suggest

3C0 145 117F Seal Ring x1 £4.60

3C0 145 117H Seal Ring x1 £3.53

Just an update. Driving home tonight I managed 42mpg trip computer! I was stunned and had to look twice! I wasnt driving economically either and just driving the speed of the traffic in front!

Just an update. Driving home tonight I managed 42mpg trip computer! I was stunned and had to look twice! I wasnt driving economically either and just driving the speed of the traffic in front!

Grrr, I'm having to wait for the engine mounts to be done (precat coing out at the same time) due to the workhorse abruptly dying on swmbo the other day! :(

I am still impressed by this free mod. Driving home last night presin gon, not going mad but quick enough. I still got 32 mpg where as previous times would have been only getting 26-27. Still its better than about 9mpg that JannerSy was telling me about yesterday

Just bumping this up to see how things are several months on?

Still haven't managed to get mine removed as the mounts were sold on, also swmbo got a new car which has demanded my modifying attention...... I think I will have a go myself in the next few weeks.

So I can remove this pre-cat on my TSI at any time. It will:

Make my car quicker

Will make mpg better

Make the car slightly louder

Will still pass MOT

Costs next to nothing.

Surely everyone should do this then?! There must be some negative.

So I can remove this pre-cat on my TSI at any time. It will:

Make my car quicker

Will make mpg better

Make the car slightly louder

Will still pass MOT

Costs next to nothing.

Surely everyone should do this then?! There must be some negative.

As the current UK MOT test does not include a cold start test so I personally can't see any negative, however a fellow mk5golfgti forumite has mentioned it's illegal modification, he is a continential dweller however!

When I had a vectra Sri 150 I bought a new cat and it didn't come with a pre cat. I don't think there really needed in the uk it just helps with emissions in europe same with the EGR valves.

Mine is a TFSI also. Last MOT I still had the precat fitted, this MOT I didn't have a precat fitted. My emissions results were exactly the same for both MOT's and the car easily passed.

Precat removal piccies:

What is all that stuff in the top picture? If I understand the pre cat underneath that stuff is the pre-cat.

The first picture shows the bits of Pre-Cat material as I was breaking it up with a screwdriver.

Also the car has just flown through another MOT emissions test with out the Pre-Cat.

has anyone done a before/after dyno with this mod?

I have experienced no side effects after removing the precat. I am going to get my car dynoed at Bens (shark performance) to see what it is putting out. However it will not be a good comparison for before abd after as I have fitted some SFS boost hoses this week and they give about 10bhp increase in power. Though with the precat removed and the new hoses on it really shifts now. I am torn between getting Ben to tweak my stage 1 map to a '1.5' to compensate for the precat removed or go for a sports cat downpipe and stage 2. I really doubt there would be much difference in performance between the two and I would save a few hundred pounds with just getting a new map. :wonder:

I have experienced no side effects after removing the precat. I am going to get my car dynoed at Bens (shark performance) to see what it is putting out. However it will not be a good comparison for before abd after as I have fitted some SFS boost hoses this week and they give about 10bhp increase in power. Though with the precat removed and the new hoses on it really shifts now. I am torn between getting Ben to tweak my stage 1 map to a '1.5' to compensate for the precat removed or go for a sports cat downpipe and stage 2. I really doubt there would be much difference in performance between the two and I would save a few hundred pounds with just getting a new map. :wonder:

Good to hear things are scwheet!

Where did you get the boost hoses from and how much - I like the 10 bhp figure!

Seen this kit on the bay!

How do silicone boost hoses give 10bhp increase?

Martziniuk,

Have a read here:

http://www.mk5golfgti.co.uk/forum/index.php/topic,4261.0.html

With the SFS hoses there is far less leak potential. OEM hot side piping is made up of 3 parts turbo to intercooler, SFS is just one hose. Also same for cold side.

Hmm not overly convinced. Completely air tight pipe work should give similar sort of power in theory but O.E pipe work seals aren't very good so yes good upgrade.

I got them off a member from the Mk5gti forum. Boost hoses and coolant hoses for £175 and never been fitted...bargain me thinks. They have changed the cars perfomance, even swmbo has commented that the car sounds different and goes quicker.

Hmm not overly convinced. Completely air tight pipe work should give similar sort of power in theory but O.E pipe work seals aren't very good so yes good upgrade.

The sfs hose from off the turbo is much bigger than the OE one and there is no kink like in the metal hard pipe. Also the sfs hose is straight with out that bend just before it goes into the intercooler. The intercooler throttle body pipe hose is much larger to and flows more air. This is where the increase in power comes as the hoses flow the air easier than the OE design. I will post the graph once ive been to Shark

I got them off a member from the Mk5gti forum. Boost hoses and coolant hoses for £175 and never been fitted...bargain me thinks. They have changed the cars perfomance, even swmbo has commented that the car sounds different and goes quicker.

Are they the same hoses in the link I added? 8 in total.....

The sfs hose from off the turbo is much bigger than the OE one and there is no kink like in the metal hard pipe. Also the sfs hose is straight with out that bend just before it goes into the intercooler. The intercooler throttle body pipe hose is much larger to and flows more air. This is where the increase in power comes as the hoses flow the air easier than the OE design. I will post the graph once ive been to Shark

Can you post some pictures?

Pics of mine are here on page 4: http://www.mk5golfgti.co.uk/forum/index.php/topic,4261.0.html

Pics of mine are here on page 4: http://www.mk5golfgti.co.uk/forum/index.php/topic,4261.0.html

Any of them fitted??

Pre-cat removal academic now, as I have secured a deal on a Miltek DP with 200 cell sport cat.....

Are they the same hoses in the link I added? 8 in total.....

Can you post some pictures?

The hoses you have posted are the coolant hoses and not the boost hoses. Nice you have got a DP Just remember to get a reducer pipe if you have an OE cat back exhaust as the milltek doesnt have one built into the downpipe..

I just cant help but think that the OE down pipe with the pre cat removed wont be many miles away in performance than a sport cat. In the OE DP the pre cat is the biggest restriction. It will be interesting to see what the graph is and I might see if Ben will put a stage 2 map on and run it on the dyno to see how much it would need to be backed off.

The hoses you have posted are the coolant hoses and not the boost hoses. Nice you have got a DP Just remember to get a reducer pipe if you have an OE cat back exhaust as the milltek doesnt have one built into the downpipe..

I just cant help but think that the OE down pipe with the pre cat removed wont be many miles away in performance than a sport cat. In the OE DP the pre cat is the biggest restriction. It will be interesting to see what the graph is and I might see if Ben will put a stage 2 map on and run it on the dyno to see how much it would need to be backed off.

I hear what your saying, but iirc the OEM cat has something like 600 cells, plus the Milltek is a larger diameter so I think the difference will be quite significant. What you could do is have your cat removed and replaced with a straight pipe, if you had flanges welded to all 4 ends it would be a 15 minute job to swap at MOT time, I can tell you from graphs posted by a member on the mk5 forum that power early on is ridiculous!

Have a look on there for info on decats by user hurdy.

I have pipewerx decat and spoil up is ridiculous. I had done precat removal before which helped but I didn't really notice any performance benefits also i noticed my timing pull went from 8degrees down to almost 0 with decat.