IVA fail: emissions

[alackofspeed]

Sounds like ecu is seeing a lean signal, correcting by maxing out the +ve fuel trim, hence the lambda value and emissions result seen at the IVA.

I think sadly that Saturday's test will prove nothing other than no change since IVA.

I think the best test from here is to rig up a AA battery with a potentiometer, set the voltage using a multimeter, then put that known voltage to the engine bay sensor plug (with sensor disconnected). If the ECU reports the correct voltage, then at least you know the ECU isn't telling porkies / the wiring is okay.

Shouldn't have thought there'd be a voltage drop in the wiring from the sensor to ecu, as theoretically there's no current flow in the signal wire.

To confirm, you have the following?

2No white - 12v from battery via a relay.
1No black - connected to ECU lambda pin (D14?).
1No grey - connected to the SAME earth as the ECU?

[MadDogMoggy]

Ok this has got me thinking!

My assumption was that the ECU fed the O2 sensor with a current/voltage and measurd the voltage drop (ie the variance in the resistance of the sensor, which change with the amount of oxygen in the exhaust gas)

Bearing in mind the following is from my build notes - I've not actually looked at the car this evening.

I wired up the ECU following RichH's wiring diagram, which was invaluable.

The connections that I have are:
E1 Fuel relay coil
E4 O2 Sensor -ve (grey wire)
E7 Main relay coil
E9 Relay for O2 Heater
E26 RPM feed
E31 MIL feed

A1 O2 Heater (now disconnected)
A2 12v feed from main relay
A3 12v feed from main relay
A6 O2 Sensor +ve (black wire)
A18 Speedo
B8 Fan relay

The ECU doesn't appear to have an earth (not via a pin anyway), which is a bit confusing!

I've looked through a PDF of a manual which has some pin outs for the ECU, but I'm not sure if it cover the Type R. Interestingly:
A4 and A5 are listed as grounds for the ECM circuit
A16 is AFS sensor (-ve)

E4 is just listed as 'sensor ground'

Could this mean then that a) my ECU isn't earthed properly, and b) my O2 sensor is wired wrong?

There also seem to be a lot of other connections missing (like those to VTEC solenoid)!

I'm wary of adding/changing wires in case I damage the ECU!