chris_c201

Hi All,

Planning on fitting a decat up and down-pipe to my Bugeye WRX so taking out two cats.

On the downpipe there will currently be an EGT Sensor, the new pipe doesn't have the hole so i plan to leave the plug off and use the 2.2ohm resistor "trick".

On the up-pipe i am putting in again there are no holes, what is there currently and what implications will not have these sensor possibly have? Will this all be tricked by the resistor so i don't get a CEL?????

All of the above may be wrong so i'm open to any advice....

Cheers,
Chris

Rice Rocket..

Hi Chris,

like you i got this done ALONG time!

My Downpipe doesnt have any sensor in it, my up-pipe does, I think its the lamda, may be wrong and the exhaust headers has the EGT in it or it could be round the wrong way!

I think the best way would be to leave the car over night and remove them when they're cold to save any thread damage

Good luck & watch the knuckles!

Ricey

DubaiNeil

As far as I found on a MY02 bug-eye:

Decat downpipe - the (very) occasional P0420 CEL is thrown, but that is with the EGT still in and connected. I bought the 'CEL fix' from JW Racing http://www.j-w-racing.co.uk/cgi-bin/...%23a1246#a1246
but never felt the urge to fit it, as the instructions suck!

Decat up-pipe - this the 2.2K resistor trick. I fitted the resistor then taped the two parts of the electrical connector back together so it can't easily be spotted. You would obviously remove the EGT sensor and lead, but you should seal the connector with the resistor fitted to avoid cr*p getting in if you ever need to revert tostandard.

HTH

Neil

chris_c201

Cheers guys,

For the downpipe if i don't have the EGT in at all then is it more likely that i will get the CEL, does the sensor / ECU look for a tolerance or only when the sensor detects a temperature above a certain mark.... if so then surely if the sensor isn't in the pipe it is never going to actually read a high temp at all....

I'll do the resistor for the up-pipe then, one thing to clarify though Neil.... The up-pipe i'm putting in doesn't have a hole at all so i will "tuck" the sensor out of the way somewhere and seal it, when you say seal to stop rubbish getting in, what part do you mean, the actual sensor or the connector?

Ricey - Did you do the job yourself?? I seen you in the shell on pollockshaws road yest although i was in my bro's Vectra....

Cheers again,
Chris

Oh, one last question - How much wrap would i need for a downpipe ??

DubaiNeil

With no sensor in place I would have thought you would get a CEL, as the sensor acts as a variable resistor - so the value reported can be too low as well as too high. The 'official meaning of P0420 is Catalyst System Efficiency Below Threshold - which means the values reported are not within the expected range.

The up-pipe sensor wire terminates at the set of connectors on the plate near the boost solenoid (under the black plastic cover with the two 'thumb' screws).
All I meant was that you would have an 'open' connector (i.e. without its male or female connector partner) if you don't have the sensor, wire + connector fitted (which you obviously won't need).

This 'open connector' was all I was referring to

Hopefully this makes sense, I'm just glad my weekend starts in 1.5 hours!

Rice Rocket..

Yes Chris that was me, no one else lucky enough to have such a good looking bugeye ;-) As for the wrap, no idea, mine arent wrapped but could be a future mod.

lol

RR

ps AWD did mywork.

DubaiNeil

And another thing - have you had any remapping done - and more importantly are you planning to? Removing the two cats in the exhaust seems to have a large impact on the AFR's, meaning you could run dangerously lean if its not reviewed.
When I changed to the decat up-pipe (the rest had been done previously) the tuner had to add loads of fuel as it was apparantly lean everywhere across the map.

chris_c201

OK, that makes more sense.

I think i'll takes my chances with the CEL and see how it goes, then if i get the CEL from the downpipe i'll worry about that afterwards and possibly look at the CEL fix, £40 seems quite a bit though....

Neil - Enjoy your weekend then!!

Ricey - No mistaking your car!!

chris_c201

Not had any mapping, it will get done but not for a couple of months, spoke to a few folk and i've been advised it should be ok for now.

I'll be leaving the centre cat in until nearer mapping time when i will remove this, upgrade the fuel pump and then get it re-mapped all within a short time....

Ricey - Are you not running a full decat with no remap?

moto

Check out this thread, http://forums.nasioc.com/forums/showthread.php?t=443943.
It explains how to do the up pipe CEL fix with a photo. I did it in about half an hour. I've kept the sensor in the garage in case I go back to standard sometime. You just need to tape up the connector with the resistor in it.

Rice Rocket..

Chris,

I've had a full decat for the last 4yrs with no remap, fueling is a ok as of the last RR day at dasteck when i was on, everything was sweet as a nut, some folk on sidc may differ, but what do they know - **** ALL!

Just go and get all the cats removed and enjoy it.

This is Neils weekend ;-)

Ricey

chris_c201

Ricey - Nice to hear!! Did you notice a difference when they were removed? What did you RR at and was it just with the decat and a filter?

Cheers,
Chris

P.S - Moto, cheers for the link, much appreciated!

Rice Rocket..

With that I got 267/240 so the you cant complain with a full decatt and at the time a Blitz induction kit.

You do notice a BIG difference with the down pipe and then a bigger difference with the uppipe.

RR

DubaiNeil

Ricey,

Not my weekend yet - we get Friday/Saturday, as we report into Europe and can't have only three days per week of interaction. Still feels like the weekend though as I have run out of work!

Neil

Rice Rocket..

Neil, your lucky I will give you some of mine if you havent anything to do!

You got any good sites you could PM from Dubai?

RR

chris_c201

267 without a remap... thats pretty impressive...

I'm not looking to get it RR'd but with my filter, cold air intake and a decat i was only expecting about 240ish tops....

As long as i can "feel" the difference i'll be happy!!

Midlife......

iTrader: (2)

Chris

I just thought'd mention that an EcuTeK remap will remove the CEL P0420 without the need for a CEL fix

EcuTeK cannot map out the EGT CEL and a resistor fix is needed.

Midlife.....

chris_c201

I thought that with the ECUTEK remap, so do the resistor for the up-pipe sensor then maybe ditch the downpipe CEL fix and wait until i remap then.....

Cheers for the info, any update on how much wrap for a down-pipe, is it just the wrap i would need, what about the spray / paint i have heard people mention?