32 replies to this topic

[Jim_Cross]

What does removing the pre-cat do (e.g. make the exhaust freer-flowing)? How much of a noticeable effect does it have? How much does it cost to have done? Who can do it? Ta muchly, Jim

[turboman]

Hi mattie. Having it removed will be approx £100 (depends where does it) the main dealers wont do it obviously. Figures of 15 bhp have been quoted by the guys on the site, all I know is that when Mike took me out in his, it made a world of difference. Most tyre and exhaust places will do it, but I'd rather use one thats done a few already, next time I see you I'll but you in touch with a few people. Have a nice day.

[Jim_Cross]

Excellent, thanks Wayne

Edited by Jim_Cross, 19 April 2003 - 04:33 PM.

[griffo]

Pre-cat My advice would be to do it yourself. That way it's likely to be done right. a) raise rear of car and remove rear undertray remove heatshields from top of downpipe (this is a bit of a bugger and takes a while). c) remove both oxygen sensors d) with long socket extension remove three bolts holding pipe to manifold (spray with Plusgas to ease them up a bit first). e) Remove the three bolts (again use Plusgas) connecting the downpipe to the rear silencer. f) remove complete pipe including catalyst by sliding off the big rubber grommet. you will now see the pre-cat in the top of the downpipe. Removing it is a time-consuming bugger. a) First drill a series of close quarter inch holes all round the edge. (frequently dip drill bit in oil cos it'll get very hot). Then chisel the whole lot out with a cold chisel or similar. c) wearing a dustmask, grind out any remaining bits with a flap wheel or similar. d) finally, use a powerful vacuum cleaner to suck out any little bits/dust etc from the pipe. re-assembly is basicly the reverse but use copperslip on all the manifold and pipe nuts. cheers Griffo.

[wellsy]

How does this effect it passing it MOT? Does anyone know if regal will do the work, as I'm hoping to get the stage one fitted in about a week?

[Jim_Cross]

Thanks Griffo. Unfortunately, I'm about as technically adept as a goldfish when it comes to cars so I ought to leave it to someone who knows what they're doing. Thanks for the tips though

Wellsey, AFAIK it is not required for the MOT. I think the pre-cat is there to reduce cold-start emissions for countries with stricter emissions regs, and the VX passes the MOT with out it.

[griffo]

Definitely no affect on the MOT since the pre-cat is just to satisfy Euro Encap emissions legislation which has not come into force yet and will only affect cars first registered AFTER 2005. You are correct -- it is only for cold starts, which our MOT testers cant check anyway. It will also not put on your engine management light (which removing the main cat does). cheers. GRIFFO

[cheeky_chops]

Hmmm, I'm with you Jim - technically not too good! And I cant be arsed! And i'll get dirty nails ! But as you say, dont really trust kwikfit or similar to clean the pipe out afterwards - could the soot/dust damage the cat if not cleaned properly? Fancy earning a few bob Griffo ?? ???

[VEX]

Cheaky Chops. Our local Hi Q dealer in Fenny Stratford, MK was the one that started all this. R3D VX was the first to get it done, and they did it. Hoping to get mine in there over the next couple of weeks. Cw.

[Purebob]

Soooo.....for a ton, we get the pre-cat chopped out of the exhaust and with absolutely no pain, we get 160 horses? Where do I sign up ? Do you have to inform the insurer? gordon bennet, imagine trying to explain what you've done to a help desk person at NU ?

[andym172]

I've got a mental target of 170ish bhp solely due to the fact that I don't like the thought that I've gone to a lesser powered car (from Clio 172). Stupid I know! - The VX is faster, but I would still like to get to 170ish bhp

So I'm thinking:

Get rid of pre-cat
Tube Torque Exhaust
and perhaps a Regal stage 1 remap.

How much does the K&N filter give? And how loud is it?

Thanks!

Andy.

[griffo]

"Fancy earning a few bob Griffo" I'd be delighted to help you guys out and I have a well-equipped workshop. Problem is I live near Falmouth (Cornwall) -- so if you are down this way, or fancy a trip, I'll de-pre-cat your exhaust for you (takes about four hours to do properly). FOR GOD's SAKE do not let the spotty teenage wankers at Quickfit anywhere near you beloved VX220. If thats the only option do not do the job. It is a straightforward procedure but it takes a degree of intelligence and experience, which regular exhaust fitters frankly do not have. cuddles GRIFFO ps my phone number is 01326 378291

[cheeky_chops]

Vex - yea, Turboman suggested them but i am on the "Griffo" side of the fence as my car is shiny new and working fine at the moment! I take it R3d VX was happy with his pre-cat removal???? Hmmm, so what could they fcuk up? Griffo - thanks for the offer!! Cornwall is a mother of a long way for me!! What do you replace the pre-cat with? Or do the 2 original pipes fit back together?? CC

[R3D VX]

I have to stand up for the guys at Hi-Q here. They did a very pro job. i have taken all my car woes there recently, they fettled my Supra TT (springs, caliper re-con etc..), lowered my VX with the SPAX and sorted the Pre cat, no worries. i actually helped with the pre-cat removal. The only thing that did get annoying was the phone and other customers wanting tyres etc... The boys had to see to them while working round me. I paid a small cash sum for the job which suits me fine, if you book your car in then i suppose they will be charging you by the hour so they will devote 100% of their attention to your baby all the time. i think 160BHP is a little optimistic from just the pre cat, I have K&N induction, Pre-cat out, Vx sports exhaust and the Regal software. i think i have approx 165-170BHP at the mo. Looking at minime's car, it has 185 ish and the inlet manifold should free 20 horses. Thats my next mod when funds allow. Hope you find a solution, Mike.

[cheeky_chops]

Thanks Mike - just what i wanted to here! Gonna get down there and see what cash they require....

[rasputin]

would you have to tell the insurence about this mod? ohh bugger more expence:9mm:

[cheeky_chops]

Just had my pre-cat removed today Briiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiillent.

Who, where, cost,sound,power?

[rubber]

Griffo I'll try again would be interested in the pre cat removal if offer still stands? cheers Ian

[cheeky_chops]

If you remove the precat - what do you replace the missing bit with??? And what do kwik fit use?