Twin Turbo O2 sensor(s) with DFI

Mark E.

Jul 20, 2001
I am helping wire up a race car using and older DFI. It will be a twin turbo setup. Do we need to use 2 O2 sensors, or can we just use one on one header? If we use 2, how do I connect them to the ECM?

Also, I know we don't use the MAF, so I assume the input to the ECM does not need to be hooked up at all. What about the wastegate solenoid, EGR, and charcoal cannister purge solenoid? I know the stock ECM will set a code if it does not see the wastegate solenoid, but does the DFI care?

Thanks in advace,
You can only use one O2 sensor and you will have to pick a side to install it on.

The MAF should be removed but in most cases, the MAF signal wire is jumpred to the MAP signal wire and used to route the MAP signal to the ECU because in a TR, there was never a direct connection from the MAP sensor to the ECM. The MAP was only used for the dash boost gauge.

The wastegate solenoid, EGR and cannister purge are not controlled by the DFI. No problem leaving them disconnected.

Thanks Lance. That was a lot of help. I am sure I will have more questions coming soon. :D