John Thompson

This weekend, I have had fitted a Scorpion stainless exhaust system to my WRX (MY2001), removing the cats as well.

The power gain was instant. However, the Check Engine warning light (the little yellow engine indicator) has now come on. I presume that this has something to do with the modification, but I do not know why it is displayed, and neither to the (reputable) company who fitted the system. I have chosen tho leave the car on the drive until a solution is found.

Bearing in mind that the mod is not a Subaru approved item, I am sure my local dealer will have no interest in the matter. Can anyone help?

Kevin Greeley

Check the wire that goes to the sensor in the downpipe - it might have fallen off?

Shark

To change the down pipe you have to swap the O2 sensor from the old catted downpipe to the new one. Check it is fitted correctly and connected to the loom. A bad connection will almost certainly cause the check engine light to come on.

The fact that the exaust has been changed should not cause the problem, unless the O2 sensor is damaged or faulty.

David

Shark

PS - with regards your dealer, you are on dogey ground re warranty to the letter of the law. The dealer is able to check the fault codes on select monitor (Subaru's computer thing) but as you have fitted non standard parts they will probably charge you.

Kevin Greeley

Watch out that you don't tread in anything on that dogey ground

Thought it was the O2 sensor but couldn't remember.

Fullonloon

It could be that they haven't fitted the sensor back on to the new downpipe, as there wasn't a space for it. This will cause the light to come on.

ollyshorey

John,

Cant help with the light. Sorry.

But ..

Exactly how much more performance are you getting. + What exchast is it ??

Pete Croney

So none of you lot have an 01 then do you?

The owners manual would have given the answer John. A non flashing engine symbol means that the OBD unit(on board diagnostics) has picked up a fault with the cat. Only European models have the OBD system. The Select Monitor will show error code 0420 "Catalyst below operating threshold". The OBD system can now detect misfires too, as these would damage the cat (if it wasn't now in the garage ).

The only way to remove the error code is with a Select Monitor. The 01 does not have the black plugs under the dash.

There are two ways of resetting the ECU with the Select Monitor... through the OBD system, which can be done without turning the engine off (protects all learnt data) or by a full reset as on previous cars (car runs like a dog for approx 20 miles).

The new car has two O2 sensors. The rear one is in the second section of the exhaust (there are 4 sections)

If you use SUL, your car may be alright. My light has come on once in 2500 miles. Using 95 octane, it will come on immediately.

When the light does come on, the engine operating perameters do not change. I was told that the boost was reduced, as in "limp home mode", but this isn't the case.

We are working on a black box which will modify the rear O2 output, giving signals as if the cats were still in place. This will be available with our downpipes.

Incidentally, the car does still have a cat. It is in the manifold. Because of the heat at this position in the exhaust, this cat will be VERY efficient.

To remove the light, you will have to get your dealer to clear the code with a Select Monitor.

chiark

Hmm, surely the shop who fitted the exhaust should know all about this? If I were in your shoes, I'd be getting my money back on it as it just isn't right for the car!

If they don't know about this, should you be trusting your pride and joy to 'em?

Is the exhaust designed for the MY01?

Hearty Congratulations to Pete C and Scoobysport for doing the necessary research on this one! Anyone can yee-haw an exhaust on, but it looks like it takes a bit of knowledge to do it to the MY01.

Pete Croney

On the subject of this...

My office took a call from Magnex.

They asked me to approach the SIDC members as they would like to borrow an 01 to design their exhaust.

They will need your car for 10 days, but you will get a free Magnex exhaust.

Contact their office if interested.

(you don't know how hard that was )