hello all does anyone know where the purple wire on an a/f ratio gauge go on an 03 wrx i'v checked scooby mods and i don't understand where b17 is. its a white wire but there are to that i see where it might supposably go here is a pic of my ECU if it comes out just tell me where it goes and which white wire could you guys please thank you

 

here

 

I think it's the same as the 02... hold on let me show you which one i think it is. Most likely you'll be using the Rear oxygen sensor to hookup a A/F gauge.

According to the FSM for the 2002 it's terminal 17 of connector B135 which appears to be the same looking connector for your ecu.

Jon

 

by the look of it B135 connector should be the second to the left on the picture that you posted. the rear oxygen sensor wire that you'll need to hook it up to should be #17

Jon

 

It may also be the one second from the right. Reason I'm not sure is because the picture isn't that great!. You'll have to count the number of wires on the connector to tell which one you'll need. They are all different so don't worry about getting them mixed up. Also they cannot go anywhere else but in one particular spot on the ECU.

Jon

 

OH I also forgot to mention that the A/F wire should be WHITE

Jon

 

Here's the other ones maybe you could compare and see if they are the same. I'm pretty sure that are though! Don't quote me

Jon

 

well i know one thing it is b17 a white wire on b135 which one on my ecu is b135

 

by looking at your image it could either be the 2nd from the left or the 2nd from the right... you'll have to count to find out.

Jon