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Old 06 Nov 2007, 10:33 PM   #1 (permalink)
bmd
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lambda sensor

hi guys
as posted last week, i now have decatted my 04 wrx, plus an induction kit; i haven't noticed a massive difference in power (tho she sounds awesome ) and was told this is 'cos the lambda sensor was removed then refitted to new system; the yellow engine-management indicator continues to shine as well, again the guy who fittted the new exhaust says it may take a few days for the engine to adjust to the new system, giving more power, and then for the light to go out;
is he bullshi__ing or has he got a point?; i don't want to complain to the exhaust supplier about no increase and then have to apologise a week later

thanks folks
billy
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Old 06 Nov 2007, 11:03 PM   #2 (permalink)
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I were under the impression on later cars ya needed a celfix
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Old 07 Nov 2007, 10:12 AM   #3 (permalink)
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hi dave
further to my last post, the yellow eng-management light has gone out now (wed) so i presume all is ok? i haven't given her a warm up since this to see if there is any performance difference; can you tell me more about celfix as it's new to me, do you believe its needed for all aftermarket systems?

cheers m8
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Old 07 Nov 2007, 11:02 AM   #4 (permalink)
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Hi Billy.

CEL fix, It stops the rear CEL code P0420 Catalyst System Efficiency Below Threshold/CEL light issue appearing, being caused by aftermarket exhaust systems not having a catalytic converter in the systems.

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Last edited by 2002pete; 07 Nov 2007 at 11:20 AM.
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Old 07 Nov 2007, 11:17 AM   #5 (permalink)
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newage will need a CELfix.

available from http://www.rogerclarkmotorsport.co.uk/
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Old 07 Nov 2007, 11:44 AM   #6 (permalink)
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right guys, thanks for that,and pardon my ignorance, but does she need a celfix...
1/ to allow the engine to release more power with the decat system now fitted, or

2/ simply to remove the eng-management light on the dash (which has now gone off)?

i refitted the lambda sensor to the new system, does this affect wheteher she needs a celfix?

cheers
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Old 07 Nov 2007, 12:01 PM   #7 (permalink)
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the celfix is to ensure the cel light does not come on.

the cel light may come back on again.
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Old 07 Nov 2007, 12:07 PM   #8 (permalink)
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many thanks jd, time to take her out for a spin and see if there's any difference, and whether the light is on or off!

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Old 07 Nov 2007, 01:00 PM   #9 (permalink)
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Quote:
Originally Posted by bmd View Post

i refitted the lambda sensor to the new system, does this affect wheteher she needs a celfix?

cheers
billy

If you refitted the lambda (or o2) sensor onto the new exhaust system. You should not get a CEL light issue from the o2 sensor.
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Old 07 Nov 2007, 01:02 PM   #10 (permalink)
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the decat can make the o2 sensor give incorrect readings hence the need for a celfix...............i think
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Old 07 Nov 2007, 01:23 PM   #11 (permalink)
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Quote:
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the decat can make the o2 sensor give incorrect readings hence the need for a celfix...............i think
Yes Steve a decat can give a incorrect readings. Hide my head in shame.
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Old 07 Nov 2007, 01:35 PM   #12 (permalink)
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ok, so now i'm confused (wots new )
the decat system was fitted on monday, but the guy coudn't get the lambda sensor off without wrecking it, so i drove mon without it, and with the yellow light showing;
i got the sensor fitted to the new system on tue, and the light stayed on, but the guy said it would go off in a couple of days once the engine had adjusted itself; sure enough the light has gone off today, but i'm not sure if performance has increased to any great degree and wouldn't like to think i'd spent the money for nowt ;
then i read about this celfix thingymabob, and wonder if thats wots needed to release the power?
as she stands, the light has gone off but i'm not sure if i need a celfix to let the full potential out, or just for the light; now not sure wot to do (if anything)

help!!!

billy
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Old 07 Nov 2007, 01:43 PM   #13 (permalink)
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sorry pete i wrote the above post while you were replying to jd!
so, the celfix is only to satisfy the engine and to knock off the cel light? and it does not affect performance?
so if the light is already off, am i getting as much power as i'm ever going to get, whether the celfix is fitted or not?

am i right???

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Old 07 Nov 2007, 02:46 PM   #14 (permalink)
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If the cel light is off you sould have no issues. The celfix fools the ECU in to believing it is still recieving the correct signal from that sensor.
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Old 07 Nov 2007, 03:52 PM   #15 (permalink)
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like pete says pretty sure a cel fix is basically just a resistor to change the measurements gave by the sensor to trick ecu into thinking the cats are still on however as for wether its an issue when the cel lights off is beyond me, ive very little knowledge of newage cars however can tell you on a classic problems can persist without lighting the cel for example maf sensor can be knackered whilst not lighting the cel-

based on this your car could be running crap and the problem un noticed by the ecu-however i`d like to have thought subaru would have rectified problems like that on later cars.
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