De cat up pipe on a WRX remap or not?
 

I was asked the question recently and just wondered what the general consensus was should one go for a remap or not? This was asked about a PPP WRX.

Also how common is it for the WRX catted up pipe to fail and disintegrate taking the turbo with it.?

I had a wrx and found out about the cat in the up pipe... I swapped it for a decat up pipe and a sports cat down pipe (prodrive) just for piece of mind really.... Then had it mapped.... Hope this helps....

I've seen them fail and block up, but never seen an uppipe cat actually enter the turbo !

Emma's fell apart in the uppipe and it was obvious when mapped only made about 220bhp when replaced with an sti one it made 278.

Didn't cause any other problems though and has run at 278bhp for Two years and still going

i think the cheap ebay up-pipes with the flexi joint might break up and go through the turbo as for a standard one i think they just get blocked as tt pointed out

get rid of it and have a tweak

06 onwards don't have a cat in the up pipe.

Just replace with an STi up pipe, I ran mine for about 6 months with no issues. Used to give a great induction noise too. :)

Did you map for it or not bother?

I replaced the whole exhaust system, fitted an STi up pipe, Prodrive sports cat down pipe and decat centre pipe. Got the car remapped around 6 months or so after fitting.

What you will get when replacing the downpipe, is a cat below efficiency CEL.

Ditch,

Thanks for asking the question, been a manic week!

Guys, no one has addressed the question about the remap......with mine being a PPP model and if I were to swap the up pipe for an Sti one, would this effect the original PPP map and would I therefore need a remap to get the best results?

im swapping my standard up pipe for an sti up pipe nxt week and will remap it the nxt day

A wrx up pipe has a lot of restriction regarding spool, so when changed would make a beneficial increase. I'd recommend a tweak at least though to get the full potential.

No worries I was curious what peoples experiences were anyway so thought i'd ask.

I asked JGM and he said it would need a map, which obviously you would to get the Best from it, however I was wondering if it would have any adverse effects on the engine.

As it's a Maf based car with a pretty cleaver ecu I wondered if it would self learn after a short while or an ecu reset. Also with it being a Prodrive map would it really affect the car so much because of it being rich and a 260 odd bhp map as opposed to standard 225bhp map?

I'm sure it would I just don't fancy paying £500 for an ecutec remap for the sake of an sti up pipe that may or may not take out a 100 quid turbo.

Why would you need a Ecutek map on a new age car? There are other cheaper option you know.

Most mappers will tell you it needs 'Ecutek' as its the easiest thing to map, literally! £150 for licence and the rest in mappers pocket for uploading a generic map and a final tweak for your mods.

Best bet for your monies worth on a map would be to remove the cat center and downpipe too which will give the better increase.

On the other had, don't proper ppp have a sti upipe already?

Surely Ditch you would need a remap to sort out any protental over boosting? with free flowing gasses from the decatted up pipe.

No they don't it's the centre cat that is removed which is what makes me wonder if i'd get away removing the up pipe one too and my preferred mappers don't do open source or carberry unfortunately. If I were to go for a remap i'd want a 50 bhp increase to get my moneys worth so that means billet td04 as I don't think it's worth mapping for another 15bhp.

I don't know, which is why I asked the question, more to see if anyone had just said '****' it, as like I said I don't fancy splashing out 500 notes so wanted to see what peoples experience was before I fit the one I have sat in the garage.

It's just a question really to find out what potential issues would be possibly created by removing it.:)

A simple download of your rom, turn off the appropriate CEL errors (EGT etc if not reusing) and load it back on, the TD04 doesnt suffer overboost in the same way the larger turbos would.

So would I get cel errors for removing the up pipe cat? I think the sensor is in the down pipe. :wonder:

Then remove the downpipe cat then?
And your preferred mapper can't be a proper mapper (ouch! Figure of speech) as any mapper 'should' give you other options instead of pulling your pants down. But whatever's easiest for them for most money and least work ;)

Yes you would as the wrx has a EGT sensor in it, but can use the resistor trick. I did before remapping. There is no sensor in the downpipe just an o2 one in the centre pipe on the newage wrx.

please explain in more detail, as in whats the resistor trick.

I know, but you know as well as I do that there are about 5/6 mappers out of 20 or more that I would use and like I said non of the ones I want to use do open source so there must be a reason, what it is I don't know but at a guess it must be the software or back up / come back.

Yes no worries fella. Well it tricks the ecu that the EGT probe/sensor is working correctly in the uppipe. So no check light come on. It measures temperature to protect the cat I believe. You can remove the plug from the socket near the 2 port solenoid valve. You need a 2.2k ohnm resistor (I thinks it 1/4watt type? Anyway I have spares if want one) and you connect it to the socket terminal. If you car is being mapped, they can turn this sensor off so no need for a resistor,but I used this for a couple of days till mapping time with no problems and an sti uppipe in place.
Phil