Technical help required please!

[steve_nairn_sti]

Bought my 52 plate WRX last week and the CEL was on at the time.  Took it back down to the garage today and they took it round to scooby dealer in Perth.  They managed to reset the CEL and explained that with the de-cat pipe, the added heat was roasting a sensor.  (Heard all this second hand from the selling garage).  Wasn't told what sensor it was but I do have information from an e-mail that went back and forth between them.

Exact details in mail are as follows:

"I managed to find out how to clear the EGT up pipe CEL light.  I got a 0.5W, 2.2KOhm resistor from a TV repair shop and fitted it to the connector that goes to the engine management chip.  I sealed it up to keep the water out and removed the sensor altogether.  Just thought you might like to know for future reference"

Sounds a bit dodgy to me.  I don't want anything shady done to my pride and joy!  I'd like to know if the above information is correct, advisable and whether there are any alternatives.  Can anyone help me out?  Can you explain in lehmans terms what needs to be done and how much it's likely to cost please?

 

Much appreicated all.

[Gumball]

it sounds like a CEL perhaps due to the decat itself. If the subaru dealership reckon the sensor is getting melted then i would imagine they are right. Get the lamnda sensor moved from where its sitting on the centre section or downpipe. a few inches Most cars i wouldnt think had wrapped exhausts so whys yours doing it from a heat problem.

As for fixing it with anything from a TV repair shop or simply taking the sensor out to shut it up? maybe someone on here could cast their views over that aspect.

most people have decats with more sensors on their cars than they know what to do with and have no CEL.

only time i had CEL since buying my car was when i fitted a decat without maping it for a whole 24 hrs before i got scared and swapped it back

slide under the car and have a look at the lamnda sensor which will look like a spark plug with a couple of wires it could be cut or damaged in some way. in which case a new one from someone on SIDC or contact will be about 100quid max

[steve_nairn_sti]

Cheers Gumball,  much appreciated.

So if I've understood your post correctly, the Lambda sensor can be moved or at a last resort, a further remap might be required.  Is that correct?  Where would you suggest mounting the Lambda?

Sorry for my ignorance but I'm more into the driving experience than the technical knowhow jazz![:$]

[sheep]

I have a 51 plate bugeye wrx with a decat down pipe. When i got the decat i was advised that i would need a cell fix to stop the fault that you are talking about showing up, when i bought one ( i cant remember where from) i was sent a small resistor with three wires on it if  i remember correcly. I gave it to dunc at hypertec to fit for me but i dont know where this was soldered in about but it does stop the cel light from coming on.

[Gumball]

Its a tricky one in some respects. whats ever going to be the absolute correct advice?

I just know from experience with mine-

1. The lamnda hole/positioning on different exhuasts is different.

2. When i changed my system the sensor was taken off put in the same place with the new system. Only they werent identical and the subaru system held the sensor in one place, and the blitz decat held it 1 foot further up.It then mangled itself around the zort (amybe with heat) and i had to get a new one.

3. a decat is allowing more gasses to get out the back freer. i am of the opinion that you could run about all year/multiple years without a remap OR it go belly up as the car isnt sure whats happening with the gasses.

again hard to explain, but a check of the lamnda istelf and a trip to see WUZ or AWD maybe wouldnt go a miss. Run the car off boost if you want to be extra double extra safe as i would if it was me.

** again just me perhaps- but reading about the CEL fix aspect which is common practise. what happens if the CEL comes on and its something else thats wrong? you would horse through it at .9, 1.1, 1.6, 2.0 bar and it could blow up

 

[moto]

I had a similar problem with my 52 plate WRX.

Judging by the e-mail you have, the "roasted" sensor would appear to be the up pipe EGT sensor and this has brought on your CEL. Do you know if your up pipe is decat as well as your down pipe? 

When I de catted my up pipe this sensor was removed to prevent the possibility of it breaking up and damaging my turbo as it was no longer serving its purpose; i.e. sensing the catalytic converter temperature. The downside of this was that the CEL light kept coming on. I carried out the fix described in your e-mail and the CEL reset. It basically fools the engine management chip into believing the up pipe exhaust gas temperature is healthy. This causes no risk whatsoever to the car and the CEL light will still function if any other fault appears on the car.

If you're up pipe is the original item with catalytic converter, I would think about getting a replacement sensor as it has a job to do! I'm not sure how much these cost (not a fortune). Ask the guys at AWD in Perth. They are the experts.

This fix should not be confused with the down pipe CEL fixes which are available and which are unnecessary with a remap. These are for "Catalyst System Efficiency Below Threshold", this code being caused by the lack of a catalytic converter in the downpipe.

Hope this is some help. []

 

[ally-b]

The Check Engine Light is telling you that it has sensed that something is wrong []

Fitting a resistor in place of a probe will 'fool' your ECU into thinking all is good []

When getting it remapped , any good mapper will alter the parameters so that the 'alarm' range is extended , to allow for de-cats etc , and it will only light the CEL when a genuine fault occurs [H]

Hope that helps []

Al.

 

[steve_nairn_sti]

Thanks folks,

I'll pass on your thoughts to the garage who sold me the car and see how they want to progress...

JohnnyR6 - Got your PM mate and I hear xactly what you're saying![]

Fixed soon hopefully!