I'm getting a mail-order tune and didnt realize that the 2003 came with narrow band O2 sensors. Looks like the sensors can be upgraded to wide band but the connector has to be changed to the wide band style that has 5 wires instead of four. Anybody know where that extra wire runs to and has anybody else done this mod?

 

I would just get standalone with a guage honestly

 

You can't just upgrade it to a wideband. You need a new harness and ECU. Best bet is to get a standalone.