OK , given the circumstances I didn't look any further like most rookies would which I haven't been a rookie for many many years. Not to say I don't make rookie moves from time to time but this was one of them. It was a coincidence that the check engine light came on the min the new tune was written and finished loading. After all this and the predator not picking up the fault either we can assume it's the tuning somewhere...... well while doing an oil change I notice that my air intake temp sensor looked to be not all the way seated. So after doing the filter and reinstall I plug the sensor back in button it all up and wouldn't you know, no more light! The sensor must have shaken loose somehow and just when the tuner was doing its thing the light came on. Idk but it's off now!