MG ZT 260 Error Code P0138

This is the first time I have used the pscan on my MG ZT 260 as my engine warning light came on today. The software loads and works fine. There are two software format selections named Ford and T4. First question is why are there two and what are the differences?
Running the program shows a fault code P0138 Sensor Circuit High Voltage (Bank 1 Sensor 2). If I run the Ford format it says misfire not detected yet the T4 states detected. Should I be using only one? If so which one?

I don't know for sure but would suspect that if the Ford selection doesn't identify the misfire and the T4 one does, then the T4 would be the one to go for. Perhaps Philip can clarify when he drops in.

The 260 ECU is more or less a Ford Mustang ECU.
A couple of years ago I started working on the 260 by buying a Ford Mustang ECU and reverse engineering that with a Ford specific tool.
Then I got access to a local 260 and tried the T4 on that and compares the differences.

Here are some quick notes:-
The Ford tool on the Ford ECU is able to pull a lot more data than the T4 can from the 260.
The Ford tool wouldn't work on the ZT, but, I found that the "format" of the data was exactly the same.
I also found a few instances where the Ford tool gave different results to the T4.
I also found a few instances where the T4 was giving results that were clearly rubbish.

My feeling is that the protocol is basically a Ford one and that a Ford tool is probably the most accurate, however I also give the results as supplied by the T4 in case I am wrong. I think that this was a niche car developed by a company that was in serious financial trouble. There would have taken the Ford documentation, rewritten it as their own, and added in some Rover "secret source" and then handed that on to Omitec to turn into the T4. Two lots of "translation" them.

In the case were T4 says one thing and Ford another it's very difficult to know what to do, so I provided both.

If anyone on here can figure out which result is more accurate then please feed it back and I will use the information to improve pscan.

The other choice that you have is "Gateway" mode or "Ford PWM" mode. The T4 doesn't support Ford PWM and so it doesn't talk directly to the Ford ECU, instead it talks to the Gateway ECU which translates from ISO to PWM on the fly.

pscan on the other hand does have PWM circuitry and so it can talk directly to the Ford engine ECU (which works even if the Gateway ECU is dead or something), or through the Gateway just like a T4.

Really I need to find a 260 diagnostics gury and meet up and go through all of this stuff.

Here are the outputs all at tickover .
Bank 2 U/S O2 Heater fluctuates between on/off
Bank 1 U/S O2 Volts fluctuates between 0.06/0.83
Bank 1 D/S O2 Volts steady at 1.67
Bank 2 U/S O2 Volts fluctuates between 0.05/0.81
Bank 2 DS O2 Volts this climbs slowly from 0 to 0.9 but returns to 0 if the revs are lifted.
Listening to the engine there appears to be an intermittent misfire?? a put put sound at the exhaust.

I am aware that the error code could be caused by

1. the sensor
2. wiring/connections
3. leaking injector
4. catalyst

What would be a logical fault finding procedure based on the above data?

Check both lambdasensors bank1 on conction and function. I would suspect sensor2.
Some put put noises in exhaust is not directly an indication for misfire. And you should find a fault code for that.
The fuel trims should come closer together, now it looks to me that sensor2 is faulty and puts the trim of bank1 down.