scoobyluke23

im fitting my afr gauge iv been told its gotta be wired up from the ecu, what wire is it tho? and where is the ecu i have a 2005 sti 2.5

AkCustomz

iTrader: (2)

hi mate, i don't know if this is of any help to you but i fitted a afr gauge to my volvo 440turbo a while back by splicing into the lamda sensors signal wire. worked perfectly i then used heat shrink sleeves to finish off the job. i don't know what anyone on here would have to say about that method but worked fine for me . whatever method you use is upto you... good luck!

scoobyluke23

older cars have just one wire, but mine has 4 one white one black one yellow with red tracer and thicker black one im sure

joz8968

iTrader: (13)

1) Push an unraveled paperclip up any one of the wires (i.e into the back of the connector on the actual Lambda sensor's side)...

2) Turn engine on and let idle...

3) Touch a muti-/volt-meter's +ve probe against the paperclip, whilst the -ve is grounded against the inlet manifold (or other decent earth)...

4) What you're looking for is the meter to continually cycle up and down between 0 and 0.9 volts; this will be the signal wire. If not, then repeat steps 1) to 4) on the remaining three wires, until found...

5) Once determined, then check the colour coding of the wire that's on the ECU side of the connector union... then you can splice in the AFR gauge's signal wire at the ECU's pin-out end.

scoobyluke23

if i find the wire i need at the connector why do i need to splice it at the ecu end?

joz8968

iTrader: (13)

LOL. Sorry mate. No, you don't HAVE to do that - just that most people seem to do so (presumably to cut out 'hassle' of wiring through the bulkhead, etc... If you're happy to splice into the connector end, then no problem.

NOTE: Make sure, though, that you splice into the 'ECU side' of the connector union, or otherwise you'll have to undo it all - then redo the splicing - on a replacement Lambda sensor (should you ever need another one in the future).