15 replies to this topic

[dexter]

pics and how to do it on an NA if anyone has it, tried the search functions but can't find a good detailed description. cheers

[techieboy]

pics and how to do it on an NA if anyone has it, tried the search functions but can't find a good detailed description.
cheers

There was a decent guide on the site that was accessed from the DIY car care link that used to be at the top of the page - another victim of the re-luanched site by the look of it.

[joebristolgym]

In theory it shouldn't be too difficult a job, but in practise it took me ages! You have to remove the rear part of the undertray (8/10 bolts on the bottom), then take off the pipe that goes from the curved tube coming out the backbox, up to the manifold. That has the cat and pre-cat in it. When I did it I found the bolts holding the back box to the pipe you want out had corroded massively and had to be cut off. Only prob is there's very little room to manoevre anything in there. Once that is undone you then have to remove the lower small heat shield from over the manifold (you don't need to remove the big one) - that was quite fiddly. Even more fiddly is then undoing the 3 bolts holding the cat pipe to the manifold - I did it a few months back, but believe it was fiddly with a ratchet spanner and a socket with a really long extension bar on it. Once the pipe is off it's not hard to get the pre cat out - just drill all round the outside part of it until it's mostly not attached, then screw a few scres into the middle of the pre-cat and leve it out. Drill bit gets hot, and blunt very quickly though - I used 2! Hope this helps

[Whiteboy]

I would save your time and money and buy one of these with a race cat.

http://www.courtenay...p;productId=475

[dexter]

cosmic! cheers guys

[snowwhite]

I was looking for this recently and pretty much all the links in the "Useful Links" thread are dead or not detailed at all.

Best I found was linkie covers changing the entire exhaust but just look at the pictures that are relevant to the pre-cat. It is how joebristolgym has described it really. Should only take an hour or so, but I would plan for all day

HTH

[joebristolgym]

If everything went swimmingly I reckon a coupe of hours for the job, but it took me the best part of 5. I'm no mechanic, but I'm not useless either - it was the rusty exhaust bolts to the back box that scuppered me for so long!

[VX220Neil]

Just doing a search on this as I had a little look at the small heat shield around the manifold precat flange. The bolt heads are almost disintegrated! Is it possible to remove the 3 nuts with the heat shield in place? Many thanks for any tips, other than take it to an exhaust shop lol!

[VX220BOB]

Pre cat removal Jack up rear of car using the correct jacking points and make stable using stands. Remove under tray, rear left wheel and arch liner. Follow the cat sensor wires and unplug as removing the sensors can be very tight. Remove the exhaust bend to cat flange bolts, these can be very tight and corroded as you may need to cut the bolts of with a cutting disc. There is no gasket on this flange so when refitting use exhaust sealant.To remove the cat pipe nuts at the manifold you have no need to remove the manifold heat shield, but you may need to prise the shield slightly with a long bar or screw driver to allow getting the socket on the nuts. You will need a good selection of socket drive extensions and swivel joints ideally 3/8 drive. Then remove the cat pipe assembly from the manifold.Hold the cat assembly in a vice at a position so you can drill a ring of holes around the honey cone edge and the drill holes working towards the centre of the honey cone. You will need a selection of good drill bits ranging from 6 to 10mm at least 3inch drilling depth. It would help using a cooling fluid as the drills get very hot if drilling to fast. Then using a slim sharp chisel and a hammer to help remove the honey cone from the cat flange. Once the honey cone is removed remove the cat from the vice and clean out any crap dropped in to the pipe. Before refitting the cat pipe to the manifold check your gasket is ok then put a small amount of exhaust sealant to the top side of the gasket so it will stick to the manifold and stop it dropping when you are trying to refit the pipe to the manifold. Refit the 3 nuts and re bolt the cat pipe to the exhaust pipe bend using sealant then tight up all the bolts and nuts. Refit the cat sensor wires and cable tie the wires so not touching the exhaust pipes/box. Refit the wheel arch, wheel and under tray and test for the performance increase.

[Benzola]

Did mine last weekend. Guide above is compete. Couple of additions: (1) You will - almost undoubtably - end up cutting bolts off, so an angle grinder or Dremel, punches and tap hammer are a must. One CAN fit a full sized angle grinder into the gap above and around the U-Pipe (with wheel off and arch liner out of course). Just take the guard off the grinder to make it fit. (2) If you grip the cat / pre-cat pipe in a workmate type bench, you can angle it so crap from drilling out the pre-cat doesn't fall into the main cat. Be SURE to give it a really good Hoover when you (finally) get the pre-cat out. (3) Heat wrap the u-pipe before refitting (esp if your heat shield is Knackered, as most are). Magma wrap is the business, use it generously with steel cable ties. (4) You CAN get the manifold nuts off without removing the manifold "shield" if you use an extension bar on your socket and "feed in" the socket from the open end of the manifold shield. This means whole job can be done from below and no fiddling top side. (5) Be sure to fit a new gasket (manifold to pre-cat / cat pipe). I used the old one with some gasket paste. It works, but I'm not a satisfied as if I'd used a new gasket (for peace of mind). Just couldn't get hold of one in time! (6) When refitting, use a proper torque wrench and set torques right! I had a VERY close call with cross treading the manifold studs which could have been disastrous. (7) Nearly forgot and this is important! Don't try to remove Lamda's. They will - invariably - be seized into threads and you WILL f**k em trying to get them out! Disconnect Lamda cables in engine bay, feed though so nit snagged and clear... Do the WHOLE job with Lamda's in place. Despite all this WELL worth doing. Good luck mate!

Edited by Benzola, 02 August 2014 - 10:30 PM.

[VX220Neil]

Many many thanks vx220bob and benzola for clarifying the point about the heat shield removal. I shall find a gasket then before I get to it. Does anyone have a torque values chart for the vx220? Many thanks.

[KurtVerbose]

victim of the re-luanched lunched site by the look of it.

 

 

[FLD]

I didn't drill mine out.  I jammed in some snipe nose pliers and then twisted.  Essentially just rips it out.  Wasn't too terrible a job to do as far as nasty VX jobs go.

[Benzola]

I didn't drill mine out.  I jammed in some snipe nose pliers and then twisted.  Essentially just rips it out.  Wasn't too terrible a job to do as far as nasty VX jobs go.

TBH I gave up on drill & did much the same! Worked round outside edge, pulling chunks out, whacked the main "honeycomb" with a lump hammer & pulled out the remaining centre as a big chunk! Oh the joy! 

[VX220Neil]

One of the worst jobs that I have ever done on a car in over 27 years of messing around with cars! 

 

Under tray off, no issues.

 

Lambda plugs, one of the zip ties broke and I had to fabricate one after the local dealer had no clue what I needed.

 

Had to cut off the exhaust to cat flange bolts, managed to nick the u bend so it had to come out! The u bend clamp bolt snapped and had to fabricate a new bolt type thing out of an 8.8 bolt!  A trip to a mate for some quick welding.

 

Trip for some exhaust paste from Halfrauds.

 

The drilling was the easier part to be honest!!!

 

Just hope it was worth it!

 

At least when I get a new exhaust it should be a lot easier!

 

BTW It was made a lot easier by the help from this forum!

 

 

 

 

Edited by VX220Neil, 04 August 2014 - 05:18 PM.

[Benzola]

Oh mate, what a mare. Not the easiest mod in the world. Just one of those you need to take your time with.