Multiple Devices Plugged into OBD2?

I know you can get a y-splitter for your OBD port but sometimes too many signals from that port have confused the car before... Looking forward to what others have to say... I mean how many devices can you theoretically hook up to the OBD port before weird things start happening?

 

I've been using a splitter for awhile now... for my ScanGauge and ELM327.

It works fine, no big deal.

 

Same here: a "Y" cable works fine with either ScanGauge plus ELM or 2 ELMs. No experience with the PIS thing though. There is only one way to find out. Good luck!

 

Thanks for starting this thread. I had started to wonder myself, since I am considering a Car Wi-Fi unit plus an OWL car camera, where both require constant use.

Plus, another possibility for later down the road is a reader to help me get the best and most gas mileage and use out of my car's "life". Hence that would be possibly 3 OBD-2 readers plugged in simultaneously. Any thoughts or anything? I assume it would be a bit much and thus could get in the way of our legs and feet.

 

Theoretically there’s really no limit on how many devises can you plug into OBD2 with splitters. Only problem would come from if there’s to many that send messages to car (like code reader asking for information or commanding some action) or if the devises that are plugged in will draw too much power from the port and burn a fuse.

I would think that Wifi-Unit (whatever that is) or car camera won’t send information/request to car. So then only one that would send information to car would be the code reader. So sending too much data to car should not be a problem.
Power consumption vise you should check how much they all consume. But of course if the power consumption is the problem you can just connect them directly to jump start terminal or some other place where it’s not.

But the main problem is that if you connect the Wifi-Unit (whatever that is) and car camera to OBD2 instead of cigarette lighter or some other switched 12V they would stay on all the time! Prius has a small 12V battery that can get discharged very easily and will take long time to charge back up.