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Exhaust De-Cat Advice !!!

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Old Jun 26, 2007 | 09:02 PM
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Smile Exhaust De-Cat Advice !!!

Hi All,

I have just purchased a new decat pipe to replace the front cat, the one after the downpipe on my MY05 Scoob, There is a threaded hole in the centre of the pipe which I presume it to put a sensor that is from the exsisting cat ??

Do I need any other "fix" to stop any dashboard light coming on or is it straight forward ??

Mark.
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Old Jun 27, 2007 | 03:16 PM
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If you're talking about the 2nd cat (the one between the downpipe and the centre pipe), then yes, you screw the sensor in the hole. It shouldn't turn on the CEL (well it didn't on mine.)
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Old Jun 27, 2007 | 04:01 PM
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Originally Posted by Mark'sWRX
If you're talking about the 2nd cat (the one between the downpipe and the centre pipe), then yes, you screw the sensor in the hole. It shouldn't turn on the CEL (well it didn't on mine.)
Nice one that is what i wanted to hear

Means I don't have to buy another part
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Old Jun 27, 2007 | 05:22 PM
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Originally Posted by Scooby-Mark
Nice one that is what i wanted to hear

Means I don't have to buy another part
Mine came on on MY02 when i put 3" Decat on I ended up having to have the ECU tweaked to prevent it coming on (was a Fooler or something).

Good luck
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Old Jun 27, 2007 | 06:18 PM
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On the newage cars it is quite likely your CEL light WILL come on. They are different to the older cars. Ring Roger Clarke Motorsports they do a fix - £15 that worked on mine.
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Old Jun 27, 2007 | 08:22 PM
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No problem on my bugeye,not sure on the newer models.
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Old Jun 27, 2007 | 09:09 PM
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shouldnt put the cel light on but watch out for shearing the bolts off which may be seized....
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Old Jun 27, 2007 | 10:11 PM
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Thanks for the advice kind of seems its more than likley it won't come on,
Fingers crossed !!

No doubt will end up having to get something sorted when I replace the down pipe
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Old Jun 27, 2007 | 10:47 PM
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Removing the centre cat will be ok without mapping as its actually the least restrictive of the cats and wont make a big enough difference to the exhaust flow to upset the ecu. If you do get a CEL after removing then Hayward and Scott do a 'CEL fix' for about £12 which wires into the ecu - the other option of course is a remap as using Ecutek the mapper will raise the fault threshold of the sensor to prevent the CEL warning.

Its not recommended to decat the downpipe without a remap. Removing the cat from the downpipe makes quite a significant change to the exhaust flow and you will probably end up overboosting which will require a remap to sort out. If you have a WRX then it makes sense to do downpipe and uppipe at the same time. The uppipe cat on its own will not pass MOT and there is no point in leaving it as the only cat on the car. Ecutek map will be around 650, A cheaper option is the alternative offered by Jolly Green Monster (and others) which doesnt require a license fee.
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Old Jun 28, 2007 | 12:29 AM
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After using the cheaper alternative for a long while I have made a decision to switch to EcuTek for many reasons and so I am now an EcuTek dealer..

Simon
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Old Jul 1, 2007 | 12:41 AM
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Originally Posted by funkyspider
Removing the centre cat will be ok without mapping as its actually the least restrictive of the cats and wont make a big enough difference to the exhaust flow to upset the ecu. If you do get a CEL after removing then Hayward and Scott do a 'CEL fix' for about £12 which wires into the ecu - the other option of course is a remap as using Ecutek the mapper will raise the fault threshold of the sensor to prevent the CEL warning.

Its not recommended to decat the downpipe without a remap. Removing the cat from the downpipe makes quite a significant change to the exhaust flow and you will probably end up overboosting which will require a remap to sort out. If you have a WRX then it makes sense to do downpipe and uppipe at the same time. The uppipe cat on its own will not pass MOT and there is no point in leaving it as the only cat on the car. Ecutek map will be around 650, A cheaper option is the alternative offered by Jolly Green Monster (and others) which doesnt require a license fee.
Thanks for the info

You have stated exactly what my plans are, decat up pipe, sports cat down pipe, and possibly bigger turbo and STI 8/9 Intercooler and then a Remap

Would be interested to know what sort of power output I could be looking at from that ??

Mark
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Old Jul 1, 2007 | 12:45 AM
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Originally Posted by daddyscoob
On the newage cars it is quite likely your CEL light WILL come on. They are different to the older cars. Ring Roger Clarke Motorsports they do a fix - £15 that worked on mine.
The only thing the ECU wants to see is a voltage drop - do that with a 5 pence resistor!!

£15 - Fools and their money
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