OBD reader cannot successfully connect to ECU

Hi All

I am trying to connect an OBD reader to my MG TF so that I can clear an engine warning light that came up. The car is a 2004 so OBD2 compliant.

I initially connected to the car with a USB reader, this took a few attempts to connect however identified an O2 sensor fault and misfire on cylinder 3 with low fuel. I didn't notice anything strange with how the car was running when this occurred, and potentially put it down to the new catalytic converter, backbox and lambda sensor I recently had fitted.

The pc software I had could not clear the codes, and all options for suitable windows software are quite expensive. Therefore I bought a bluetooth adapter so I could use android software Carscanner.

The bluetooth unit will connect to my phone (so power is working), however cannot connect to the ECU. Occasionally it will connect via the protocol in the attachment, however this seems very basic and only gives battery voltage. I selected the Rover presets rather than MG as I presumed this would be for the more recent vehicles. This bluetooth adapter works correctly on my girlfriends car.

The usb adapter is also no longer connecting correctly either!!!

I have read and seen on the vehicle that pin 5 (signal ground) is not connected on the OBD port. I tried a rather janky jumper lead between pins 4 and 5 with some copper strands however with no avail. Do you think it is worth soldering the bluetooth adapter so that there is a better connection between these?

Otherwise does anyone have any advise on how I can get the reader to communicate and clear these pesky messages?

Thanks

I use the Torque App and a bluetooth obd2 reader. It can be a bit problematic to get it to connect up with the ecu, but usually manages it after a couple of attempts without resorting to soldering things. It does have an annoying habit of freezing requiring the car to be switched off and the app restarted, so I suspect you are experiencing similar issues.
Again the same bluetooth reader and the same torque app work flawlessly in my Honda CRV.

I bought 2 or 3 cheap ELM 327 OBD2 bluetooth readers before I found one that would work with my 2004 MG TF 135. Like David, I used the torque app. Using an android phone, all of them worked fine in my other vehicle (2013 Mercedes Vito) but, with the MG, only one would communicate with the car.

I now have a pscan, which is the best thing to have, without question. Interpreting the results is less straightforward for a numpty like me.