I just thought of something else. Or another way. Buy one of these:
from Amazon. I was surprised to see all the parameters that are available through this little thing. There are several apps out there and I have chosen Scanmaster Lite. It plugs in under the dash and can stay there. It uses bluetooth or WiFi to connect to your smart phone. I will be using mine to monitor fuel flow and MPG.
edit; The one above only links WiFi. There are bluetooth units available at Amazon also.