Finally am getting around to installing my Plx wideband DM-6 model I bought months ago for my TII and am not sure if I need to connect it to my ECU or my SAFC or connect it to nothing and install downstream from my turbo. The car is a S5 streetported TII with a Apexi SAFC. Been reading mixed answers. Heard to leave the existing o2 sensor installed since it is narrowband and add the wideband. Then heard it has to connect to the pin out of the ecu. Confused? Some clarification would help.

 

Your wideband should have a separate readout that shows on some sort of meter that you just put on your dash, or in a gauge pod somewhere. You don't need to hook it up to anything else.

The stock ECU won't know what to do with the signal, and the SAFC won't even use the signal for anything useful, other than giving you another place to read the AFR.

 

Thats what I figured. Couldnt find any threads to be sure since most of them involved a standalone ecu and not stock or piggyback. Thanks for the clarification. Glad to know Im not screwing this up.

 

I left my Stock O2 where it was,and I put my wideband on a separate bung,about 30 inches downstream.

 

That's how you're supposed to do it. Don't think that the wideband can replace the O2 sensor if you have the stock ECU, it's not going to know what to do with that signal. The installation manual will give you specific instructions on where it's supposed to go to prevent damaging the sensor.

 

Your wideband should have a 1v output that the stock ecu can read.

 

Oh wow, you're right! It does have a 0-1v narrowband output! I'm pretty sure my NGK Powerdex wideband doesn't have a narrowband output. And I paid more for mine too (7 years ago).

 

install it separately. don't touch the stock o2 sensor--you don't want to install the wideband that close anyway, and i trust the stock sensor more for doing its job