Hi All,

I purchased a 2005 WRX 2.0 last week, the car has had a full steel de-cat exhaust fitted and the emissions light is on.

I got the 10,000 mile service done last week, the guy at subaru gave me this code on the diagnostic:

P0420 - Cat System Efficiency below threshold.

They knocked the light off, however it has returned. I understand now (I think) after reading through this fantastic site, that this is due to the increased pressure/temp through the exhaust.

I have been quoted £500 for a remap to remove the problem only (no performance change)

I cannot afford that at the moment, because all I seem to do at the moment is spend money on petrol

Does anyone know of a method to permantently disable the light (without removing the bulb)? Somebody suggested that I can get a turbo bypass pipe or something, but that is foreign to me.

Many Thanks for looking.

 

you need a cell fix due to the decat,just a resistor needed i think,but others that have done it will give more info....... no remap

 

Find someone who has a proper tactrix cable and openecu, they can do it.

Or buy one yourself, dont quite know how much they are now as I have had mine a few years, but should be less than 150 quid.

Do a lookup on Scoobypedia | Trusted knowledge for everything Subaru | Scoobypedia / Scoobypedia , that should give you the info you need.

Seems a bit rich paying re-map prices just for checking one box and disabling the CEL code, Unless they map the car to run better so CEL isnt caused, then I could understand it.

 

Thanks for your help guys. I have made an O2 sensor extension which seems to have solved the problem.