MSefi.com read only forum (Jan.15,2018)

Hi, I understand that the wideband O2 sensors are used for engine tuning. They are supplied with a bung in the LC1 kit to be welded on to the exhaust pipe.

When tuning, the O2 sensor is plugged in to the MS. When you are done tuning the engine, do you remove the wideband O2 sensor and let the MS 'do its thing'?

I hear that it's a bad idea to leave wideband O2 sensors in the exhaust for too long as it degrades them. At that point, what does the MS use for feedback? The regular narrowband O2s?

- Dan

Once it's properly set-up, the MS doesn't require feedback, although you can configure it that way if you like. IOW, you can remove the O2 if you like and let the MS do it's thing or you can leave it in place to provide feedback, it's your call. Personally, I'd do the later unless you have need of the LC-1 elsewhere.

The O2 sensor won't degrade much if it's in continuous use with unleaded fuel. The sensors don't like lead and they don't like to be in the exhaust when they're not powered up, so if you're not using the LC-1, pull the sensor out and plug the hole.

I dont understand. I thought the MS needs feedback from the O2s for EGO parameter.

Where do stock O2 sensors come into play with MS? I'm confused, please help.

Thanks,


- Dan

Most people don't continue to use stock narrow band O2s with megasquirt. All the installs I've been involved with had permanently installed Wideband O2s for closed loop EGO correction.

But you don't HAVE to use closed loop. Once you're tuned, assuming you're all set up right through and through, open loop should keep you in the ballpark.

As far as I know, only an unheated wideband sensor is damaged when left in the exhaust with the engine running. Just make sure the sensor is heated whenever the engine is running and it should be fine!