MY53 wrx with sti uppipe decat with sensor removed
 

Ive now replaced the cat uppipe with a sti uppipe on my wrx. Is the sensor a heat sensor for the cat or something and does it really need to be plugged in. What does it do. Does the sensor need to be left pluged in and leave it tied up in the engine bay, just that im away in the car at the weekend. Im haveing the mapped queak by duncan now its running full decat

It's an exhaust gas temp sensor. Not required (only there to give a warning if you're about to fry that cat TBH). You can either push a resistor into the connector to prevent an CEL error when removing it or have the error code mapped around.

what type of resistor

2.2k 1/2W IIRC

Its like a probe type sensor. Thanks for that

What would it look like or were to get one

No worries.

Have had a decat pipe sitting in my shed for ages waiting for me to get round to fitting it. Engine is coming out for a clutch and cam belt change in a week or two so it'll probably find it's way on to my car then followed by a quick remap to make the most of it and check it's not running lean afterwards! ;o)

like this

http://www.t2retail.co.uk/Electronic..._Resistor_pk_5

Yeah, just push it in to where the sensor was connected and seal with tape etc. Then get the car mapped as you won't see power gains unless you do.

did u do it urself? did u just zip tie the lead save it moving about

I'll be updating the map to block the CEL error code when I decat mine but otherwise, you just need to bend it in a U shape and push each tip of the U into the slots in the connector... way more simple than it sounds and when you unplug the sensor it'll be apparent what to do.

If in doubt, a search for "decat CEL fix" or similar should yield a How-To of two.

does every1 go with the sti 1 not the stainless 1's u see on ebay

Most probably buy after market ones as they don't know that the STi one, or one from a Classic will fit and will cost about £30 rather than £100.

there only £40 delivered with all gaskets if get used sti 1 u run chance of leak?

£40 delivered says something about the quality you're getting IMHO

not sure really as the cobra centre decat is only £69 delivered too

I had a new clutch on mine but also found out it needed a fly wheel aswel

I got my uppipe from scoobyspare and got a genuin gasket off ebay

i run the same setup on mine and used the resistor fix for the CEL.

i just fitted a classic upipe to mine which i got for £10.
removed the egt sensor completely and Duncan mapped it out.
No need for resistors or expensive pipes.
Spent more money on DEI heatwrap than anything else :lol1:

does it make a real differance removing pre cat?

Yes will make difference,turbo will spin more freely(better spool up) than with OE WRX up pipe

On WRX is worth to do,on STI i wouldn't brother because is all ready de-catted as on 06 WRX too

Just don't buy oversized up pipes from eBay you will not gain on spool,you will loose spool up

Resistor will help,but i would recommend run off the boost until is car mapped and mapper will this error remove.


Jura

it makes for more pops and bangs and noise too :D

it releases quite abit more noise too , i run it with a magnex backbox and it growls!

Until the flywheel is visible, it's difficult to know if it needs replacing or skimming. Clutch judder is usually a sign that the flywheel has slight cracks. Mine is currently OK as far a judder goes so fingers crossed I can re-use it but we'll see when I get the engine out ;o)

No extra power until you have it mapped TBH. Should enable an extra 5-10bhp peak power with a map though. The main gain is...

...so it allows you to get a broader power curve (i.e. more power across a wider RPM range) as boost will build earlier on. It'll also protect your turbo from the cat disintegrating and sending bits of precious metal at your turbine which has been known to happen.

Without a map there is a risk of running a little lean which can lead to detonation, cracked ringlands and big repair bills. However, the stock map is pretty rich so as long as you're running good quality SUL (preferably 99 RON) you should be OK.

For the effort involved in swapping it, the fact that you won't gain any extra power unless you do it and the added piece of mind, a remap is a must IMHO.

Its not just about fuelling regards being unmapped.