What specs should i be looking for when making a purchase for an obd bluetooth connector? I have see that they can be sold at different prices, what is the reason for this?

 

If you are buying BlueTooth, first thing to know is that it will not work with iDevices.

If you are using a PC or Android you will be fine.

Also they all work about the same.

 

I have a Bluetooth OBDII connector and it is iOS compatible

http://gopointtech.com/products/

Works great

 

But there are diagnostic apps for the iPhone as well, how do they work? Don't they need bluetooth connectivity?

 

And that is the ONLY one that is! The cheapo Amazon/eBay units do not work.

 

Buy a WiFi Unit. If you really want to go the distance look at the PLX unit as you can add analog inputs

 

WiFi unit?
PLX unit?
Analog inputs?

 

OK let me take a moment to write a brief explanation of the wireless OBDII interfaces.

There are several types of OBDII interfaces:

• Wired - These can be USB, Serial or even stand-alone.
• BlueTooth - These use the Bluetooth interface, they work fine on PC's, Mac's and Android based hand-held devices. The reason why they do not work on the iDevices, is that Apple wants hardware makers to pay a fee for a chip that interfaces the devices. (GOPoint is the ONLY company that makes a BlueTooth compliant devices).
• WiFi -Uses the WiFi frequencies & communication profiles. These are the most in-expensive ones if you are using an iDevices. It can also be used on PC and MAC computers.

There are several WiFi based devices, the cheap ELM327 based devices that can be had for 30$ and up. I mentioned the PLX Device it is a WiFibased OBDII reader that has an option to interface analog inputs such as:

• Fluid Temp
• Air Fluid Ratio
• Fluid Pressure
• Air Intake Temp
• Exhaust Gas Temp
• Boost Pressure

At the end of the day, if you have no interest in ever installing any of the analog / external sensors, then just buy one of the ELM327 WiFi Devices from Amazon or eBay, they work fine.

http://www.ebay.com/itm/Vehicle-ELM327-Wi-Fi-OBD2-OBDII-WiFi-Car-Diagnostic-Interface-Scanner-For-iPhone-/291101957856?pt=LH_DefaultDomain_0&hash=item43c7075ee0
I am personally running the PLX Kiwi² WiFi interface, with the iMFD analog interface and the SM-AFR Sensor Module.

I use this using an iPhone running DashCommand.

I plan to add the SM-EGT (Exhaust Gas Temperature) & SM-VAC/Boost (Vacuum/Boost) Sensors in the near future, do you need them no but you can data log using the OBDII sensors and the analog sensors, with the data logged to the iPhone and email your log to yourself and open it on a computer.

 

What's the benefit of the PLX when the OBD devices (I have an obdlink mx) read vacuum/boost, AFR, AIT, water temp without having to get separate modules? I use the torque app and it can log as well although I haven't tried it.

 

Well the reason would be that some cars do not have Wide Band O² Sensors, or the factory sensors are not always the most accurate.

 

I see. The refresh rate of the data is probably better with the modules as well huh?

 

Does the R56S have Wide Band O² Sensors?
What are Wide Band O² Sensors for?

 

They're used to measure your air/fuel ratio. The one on the mini is pretty accurate, it can be read by the OBD devices. That's why I was wondering why it would be necessary to get a PLX with a wide band module when we can already measure air/fuel ratio.

 

See I have a R53, and we only have a Narrow Band, so maybe the 2nd gen's dont need the wide band.