O2 sensor and wideband

[jakekooser]

Hi,

I just got a Zeitronix ZT-3 wideband controller and O2 sensor. My '86 Carrera 3.2 has a stock O2 sensor in the header on the driver's side, but no bung in the passenger's side. The ZT-3 can output a simulated narrow band O2 sensor output. Can I replace my stock O2 sensor with the one from Zeitronix, or should I add another bung to the passenger side?

Anyone with experience on this?

Thanks,

Jake

[jakekooser]

Nobody?

[tirwin]

I tried a PLX wideband w/ a narrowband output in my '83. It didn't work well. Long story short, my base mixture was too lean and the wideband tried to lean it out further. I swapped it for a stock Bosch O2 sensor and it was fine. I did not try the wideband again after correcting the mixture. JR and Jim Williams suggested that the Bosch K-Jetronic ECU narrowband input is very sensitive and does not react well to voltage signals it is not expecting. I can't say how the Motronic system would handle it. That was just my experience.

[mysocal911]

Originally Posted by tirwin

I tried a PLX wideband w/ a narrowband output in my '83. It didn't work well. Long story short, my base mixture was too lean and the wideband tried to lean it out further. I swapped it for a stock Bosch O2 sensor and it was fine. I did not try the wideband again after correcting the mixture. JR and Jim Williams suggested that the Bosch K-Jetronic ECU narrowband input is very sensitive and does not react well to voltage signals it is not expecting. I can't say how the Motronic system would handle it. That was just my experience.

That's correct, I.e. as a direct input to the DME ECU a wide band will be a problem.
It can be used as an AFR monitor for the operation of the fuel injection system, though.
It probably could be problematic to even use it in the simulated narrow band mode.
Just use it as you suggested as with a separate bung.

[VFR750]

I used an innovate lc1 controller with a wideband o2 sensor. Had a narrow range voltage output for the CIS system. Worked fine.

[kuehl]

Jake,

I have been running the the PLX for the past 5 years without any issues other than lack of RPM signal (PLX does not support old schoolers, non OBDII, and tech support varies like the weather). We can see either AFR or Lambda rather accurately for the value.

Unless you want to monitor both cylinder banks you only need to use the supplied
wide band Bosch sensor putting it in place of your existing narrow band sensor located in the LH header before the cat.

The unit you have has a separate narrow band output, I believe the purple wire; refer to the installation schematic. You can either run the purple wire over the DME under the seat, remove the current 02 signal wire from the DME plug (refer to the DME plug schematic to choose the right pin position and verify the wire color) and insert the purple wire its place, or cut into the existing 3 wire harness back at the original 02 sensor and provide the signal from there; be aware of which wire you use on the original signal harness and any voltage drops created by a long circuit.

You can get fancy and install a simple on/off switch for the narrow band signal.

Take some time and read up on Lambda, AFR and the relative fuels you will be using.

[jakekooser]

Thanks for the feedback. My intention is to replace the stock NB sensor and put the narrow band output of my new sensor into the DME. I am working with Steve Wong and he said that it should be no problem to use this setup.

Now, the main issue is that the WB sensor doesn't fit into the bung on my header, so I have to remove it and drill out a step that is in the bung. I have an uninstalled bung from a previous project, so I know the threads are the same, but it bottoms out on the bottom of the bung when I try to install it.

Thanks again and I'll report on my progress.

[kuehl]

I'm using a Bosch LSU 4.2, no issues with OEM bung.

Have you looked down into the port of the bung to see if the issue is something
easy (wishful thinking) like tapping through a blind lip?

[jakekooser]

I may try again tonight, but it definitely seems like the sensor is bottoming out in the bung. I couldn't get a good angle to look into the bung to see what is going on. I have ordered the gaskets to pull the header off, as it's stainless and any drilling isn't going to be fun, much less in a bad position with it mounted on the car.