02 wrx engine management light
 

Hi I've just bought my 1st subaru which is a 02 wrx.
It's done 69000 miles and had a prodrive upgrade package fitted at 10,000 miles. At some point it has also been fully decatted and had a cone filter fitted. The engine management light comes on at about 120mph.
The guy I bought it from said it would do so and thinks it needs remapped to solve it due to it being decatted. Does this sound likley as I know nothing about these cars?

If you have the airbox, Id get it refitted as it can cause problems with the MAF and results in a dead car possibly.
You will also need to get the code read, but Id guess its P0042(?) relating to one of the sensors in the exhaust system. It may need a remap, but you need to lose the cone filter.

i think the airbox is still on the car, it looks to me like theyve just took away part of the pipe and stuck on a cone filter:confused:

Get a pic up, the great and good will tell you what youve got on there.

Where the cone filter is, is where your airbox should be. It comes in through the front, in the intake you have, loops through the wing, then enters the airbox where the cone filter is.
To be fair, you would do better finding one and binning the filter there.

You really need to re-fit the OEM air filter / intake. The Newage has a very efficient intake system good for 350 BHP easily. The CEL is likely P0420 which is the cat below efficiency CEL (as the cat is missing).

You are lucky in that the DENSO ECU you have is pretty clever and has altered fuel and ignition to keep your engine in one piece, plus the fact the small TD04 turbo you have flows a small amount of air which the ECU can also cope with (just).

If you are not handy with spanners then you need to find somewhere who can help/remap the car. Opensource mapping will suit your car very well. Re-mapping will show up any weakness in your old fuel pump and you might think of swapping it for a new one if you have the cash.

Where are you??

Shaun (02 WRX owner)

I'm in Bishopton just outside Glasgow.
What does "The CEL is likely P0420 which is the cat below efficiency CEL" mean?
I don't know what ecu I have I thought the prodrive upgrade included a new ecu?
So I'll need to get it remapped anyway aswell as fitting an oem airbox?

get the standard airbox on try this one if you dont already have one
http://www.ebay.co.uk/itm/Subaru-imp...#ht_960wt_1037 as for cel light do you know anyone with a data cable to check for codes and i wouldnt put up that it happens at 120mph unless it was on a track

i have a standard air box and panel filter for sale ! 40 quid delivered if your interested.

Sounds good shaun, could u give me all the bits n bobs to fix it back on aswell?
I plan to get it checked but not till sometime after the end of the month when I get paid again as I'm a bit skint after just buying the car. Thought I'd join the forum an get some free advise from the experts 1st. I think i get you now Midlife, p0420 is probably the fault code I'll get because the cat is missing? Only thing is I've had other people tell me they had thiers decatted and havent had the engine management light come on although thiers are older models so I don't know if that makes a difference.

yeh sure, from the looks of the picture all you should need is a few bolts which i can supply. my paypal is cfnbc586@hotmail.com send the payment as a gift please. if you send the payment tonight i can get it in the post tomorow morning !

I decatted my 53 blobeye and my cel light came on about 3 months later just sitting at a set of lights just a pity your not closer to hamilton as i would put my data reader on to check for codes for you

Just sent you the £40 shaun, did you get my postal address?
Do you think that if it is the p0420 code I'm getting that putting a sports cat downpipe on would solve it? I was thinking about putting a cat back on anyway so it would pass an mot but somebody advised me against it

Just back a few posts......yep, P0420 is the classic "de-cat" CEL caused by the loss of the cats. Easily mapped out...... how about a trip to Andy Forrest :)

http://www.andyforrestperformance.co.uk/

£40 quid is a cracking price for the airbox and filter :)

Shaun

Well I'm thinking would it be cheaper putting a cat back on than getting it remapped? I'm not to fussed about losing a bit of power by replacing the cat or would I still have to get it remapped anyway?

Got my airbox today :) thanks shaun! Just put it on but can't fit my arms down far enough to get the 2 bolts in :wonder:
Also got the fault codes checked today, There was 4 codes stored.
p0340 cam sensor
p1091 intake manifold air actuator ?
p1093 fuel rail
p1131 heated oxygen sensor.
I got them cleared, took it for a run until the engine management light came back on and checked again and only 1 fault code came back,
p1131. Does that mean the sensors too hot or just faulty or what?

https://www.scoobynet.com/subaru-par...ke-system.html

theres one for sale here too

P1131 is a knackered front oxygen sensor, you need a working one of these for the car to run properly. Nose bleed price from a stealer so look at some of the breakers on here or independant suppliers like www.asperformace.com or importcarparts.

Or take the whole car down to a reptable specialist and get it checked out..........god knows what the previoius owner has done, hopefully nothing that is killing the engine :)

Shaun

looking under the car I can only see 1 lambda sensor.
Is it possible 1 has been removed since it has been decatted?
If so would it be the front or back 1 thats missing? and could this be causing the light to come on since if there is no sensor there perhaps the ecu thinks its just not working?:wonder: Also is there any difference in the front and back sensors or are they the same part?

The front Lambda sensor is accessible through a small flap in the offside wheel arch and is just visible squinting at the downpipe through the engine bay. This sensor runs alongside the MAF and ECU at running fuelling etc

The rear 02 sensor is also read by the ECU and has to be there, one of it's functions is looking at cat efficiency so removing the cats throws a CEL from the rear sensor (p0420). The sensors have different part numbers and price !!

Here's a quick diagram from an american site showing sensors/cats etc..

http://farm3.static.flickr.com/2002/...159a1c5b90.jpg

Shaun