Anybody using the narrowband output of a PLXdevices AFR gauge to drive the motronic ?

[FrankM_]

Hi,

Is anybody using the analog 0-1V output of a PLXdevices AFR unit to drive the motronic O2 sensor input on a Carrera 3.2 engine ?

Any issues ? Any tips for the installation/wiring ?

I quite like having this with the iphone display and not having to mount a permanent gauge.

Frank

[darrin]

following -- see that this uses the " Bosch LSU4.9 sensor" but don't have first hand knowledge on whether this will accurately "feed" the motronic's needs. Edit -- here's a post from Sal C that recommends the LSU4.9 sensor but mentions the importance of heater control . . . AEM Wideband O2 gauges

[Jonny042]

Haven't done it, but intend to (with an innovate), mostly to avoid having to weld in another bung.

You might need to experiment with the min/max range of the 0-1V since the wideband will react differently to the factory O2 sensor.

I've had narrow band gauges in other cars and you can watch the ECU adjusting the idle mixture by oscillating back and forth between less than and more than .5V. Not sure if the motronic does the same, but maybe through adjustment you could even stabilize the idle a bit. Both my 3.2 s have a somewhat questionable idle quality

[tmaull]

Any reason for running the narrowband to the motronic? My understanding is that this generation of Motronic does better in open loop. I run a wideband afr to monitor engine performance but it's not read by the Motronic.

[darrin]

not sure I'd be able to pass Colorado emissions with my motronic running in open loop --

[Mark Henry]

It should have two outputs, one is wide band and the other is simulated narrow band. Likely you need the simulated narrow band, which was common for 80's, early 90's cars. Simulated is just because it really is a wide band.

[FrankM_]

Yep, I know I need the 'upper right' connection with the 1V simulated narrowband, I am just trying to find out if anybody had already done it and some practical experience before buying this module (220 EUR).
Just want to make sure that it behaves nicely when hooked up to the motronic unit (keeping my Motronic connected to the O2 and keeping the cat for emissions purposes).