MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: essoman on July 06, 2012, 01:03:43 pm

Title: Pre-cat removal
Post by: essoman on July 06, 2012, 01:03:43 pm
Any of you guys advice me on how easy or hard it is to remove the exhaust and then hammer out  pre-cat ,some pictures would be a great help !
Title: Re: Pre-cat removal
Post by: DanGB on July 06, 2012, 01:31:17 pm
Are you looking to bash out the cat material?
Title: Re: Pre-cat removal
Post by: jedi-knight83 on July 06, 2012, 01:44:51 pm
Funny you mention this. I'm at the garage now waiting for him to drop my downpipe off for me to bash the pre cat out :)
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fimg.tapatalk.com%2F4f4448a3-dde2-91f0.jpg&hash=9c3b3db7980ac268cb18db4f215f1c99df20d8c5)


Sent from my iPhone using Tapatalk
Title: Re: Pre-cat removal
Post by: jedi-knight83 on July 06, 2012, 06:08:45 pm
right. just done mine. bashing the honeycomb cat material out is a 5 min job with a hammer and chisel. Just make sure you vacuum or shake out all the broken parts and dust. turn the whole pipe upside down and give it a good shake.

but getting the down pipe off even on the ramp seems a bit of a pain so how people do this on their drive i have no idea.
Title: Re: Pre-cat removal
Post by: badbwoy27 on July 06, 2012, 06:17:59 pm
My mechanic just cut out the pre cat and then welded the exhaust back up.he said he found it easier that way. :happy2:
Title: Re: Pre-cat removal
Post by: jedi-knight83 on July 06, 2012, 06:19:59 pm
My mechanic just cut out the pre cat and then welded the exhaust back up.he said he found it easier that way. :happy2:

 :surprised: so its shorter now?? really odd way of doing it. the cat material is very soft and knocks out really easily.

there is also a sensor right by the top of the pre cat so i removed this prior to bashing anything out.

Not sure how the 'cut and shut' approach would effect this?
Title: Re: Pre-cat removal
Post by: badbwoy27 on July 06, 2012, 06:32:51 pm
Mine works a dream mate. Noticed power straight away.and it was then backed up by Rtech remap where I made 256 bhp with 295 lbs torque.car runs like a dream :wink:
Title: Re: Pre-cat removal
Post by: badbwoy27 on July 06, 2012, 06:33:51 pm
Oh and thats stage 1 tune :happy2:
Title: Re: Pre-cat removal
Post by: GrayMK5GTI on July 06, 2012, 07:34:52 pm
See my thread here on this very subject:

http://www.mk5golfgti.co.uk/forum/index.php/topic,41083.0.html

Gray
Title: Re: Pre-cat removal
Post by: GrayMK5GTI on July 06, 2012, 07:36:13 pm
Oh and thats stage 1 tune :happy2:

What are your other mods?
Title: Re: Pre-cat removal
Post by: jon-tfsi on July 06, 2012, 07:38:54 pm
Here is a couple of photos from when i did mine.
The cat marerial is brittle and breaks up easily, 5 mins job  :happy2:

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fww123%2Fjon-tfsi%2FIMGP2722.jpg&hash=eaf2c4d56d1bf8c8f2f30d0d4ee53515da2d070d)

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fww123%2Fjon-tfsi%2FIMGP2718.jpg&hash=89f81e60da40afa475352a99da084969aba75f62)

Title: Re: Pre-cat removal
Post by: jon-tfsi on July 06, 2012, 07:44:55 pm
My mechanic just cut out the pre cat and then welded the exhaust back up.he said he found it easier that way. :happy2:

It would be very difficult to cut out the pre-cat. Your mechanic might have been talking about the secondary cat in the picture below.
One has been gutted and welded back up, the other is complete

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fww123%2Fjon-tfsi%2FIMGP2720.jpg&hash=ff189cab8cd850949543e12768c9bd097b7e5b5c)
Title: Re: Pre-cat removal
Post by: badbwoy27 on July 06, 2012, 08:02:09 pm
Itg and powerflow cat back,was the highest stage 1 nick had remapped from what he said. The second cat is still in place and hasn't been touched which seen for myself on Rtech ramp.just pre cat cut out and pipe welded back together.wasn't expecting it to be done this way but my mechanic said a lot easier for him. Didn't question him as he knows all about vag cars and done many complete rebuilds. He's done his own car from scratch with a mint Volkswagen carrodo with a r32 lump in running front wheel drive
Title: Re: Pre-cat removal
Post by: GrayMK5GTI on July 06, 2012, 08:14:54 pm
Itg and powerflow cat back,was the highest stage 1 nick had remapped from what he said. The second cat is still in place and hasn't been touched which seen for myself on Rtech ramp.just pre cat cut out and pipe welded back together.wasn't expecting it to be done this way but my mechanic said a lot easier for him. Didn't question him as he knows all about vag cars and done many complete rebuilds. He's done his own car from scratch with a mint Volkswagen carrodo with a r32 lump in running front wheel drive

Air filter makes a huge difference then  :drool:

I got 248.3bhp from R-tech with just a panel filter in the air box and the pre-cat removed
Title: Re: Pre-cat removal
Post by: badbwoy27 on July 06, 2012, 08:26:33 pm
Yeah itg made a big difference as soon as I had it fitted. Then had pre cat cut out and Rtech remap tweak.u will be surprised how much power itg intake makes.best mod I have invested in. Think some people just add it but I think it's better if u get your maP tweaked once it's on.havent got a boost gauge but nick said I boosted to 20 psi and then held 17 to make that power.my turbo wasn't working that hard to make that power either. :smiley:
Title: Re: Pre-cat removal
Post by: GrayMK5GTI on July 07, 2012, 12:12:10 pm
Where a bouts are you based mate? Would love to hear that twintake  :party:
Title: Re: Pre-cat removal
Post by: GarethB on July 07, 2012, 04:13:02 pm
Well if you haven't heard one by October, you'll have to have a listen to the various intakes at JKM in October Gray  :happy2:
Title: Re: Pre-cat removal
Post by: Dan.b on July 08, 2012, 04:35:13 pm
Have you noticed any increase in noise?

Title: Re: Pre-cat removal
Post by: GrayMK5GTI on July 08, 2012, 07:17:45 pm
Well if you haven't heard one by October, you'll have to have a listen to the various intakes at JKM in October Gray  :happy2:

I've got two passenger rides booked already  :grin: (yours & Robins!)

Looking forward to getting some ideas for an intake  :drool:
Title: Re: Pre-cat removal
Post by: Bigjimknickers on December 31, 2015, 10:12:02 am
Itg and powerflow cat back,was the highest stage 1 nick had remapped from what he said. The second cat is still in place and hasn't been touched which seen for myself on Rtech ramp.just pre cat cut out and pipe welded back together.wasn't expecting it to be done this way but my mechanic said a lot easier for him. Didn't question him as he knows all about vag cars and done many complete rebuilds. He's done his own car from scratch with a mint Volkswagen carrodo with a r32 lump in running front wheel drive

Air filter makes a huge difference then  :drool:

I got 248.3bhp from R-tech with just a panel filter in the air box and the pre-cat removed
Is that stock map? :surprised:  just a filter & pre cat delete?
Title: Re: Pre-cat removal
Post by: GrayMK5GTI on December 31, 2015, 01:38:17 pm
No it was R-Tech stage 1  remap also.

I'd be over the moon with an increase like that from a couple of cheap mods. . . Unfortunately not possible  :grin: