Auto Hesitant To Change Gear

[JapFreak786]

One of the auto R32's that we own,doesn't seem to like to change gear?

I'm hoping it isn't the torque converter firstly,any way that i can check this to make sure?

If not,what else is there that i can look for?

Also,the car idles at 2000rpm when left in park,though there currently isn't a 02 sensor fitted (yes i know),there is one going to be fitted on this monday coming which should hopefully get rid of the misfiring and the poor fuel comsumption

another problem,which i'm guessing is realted to the 02,is the car under boost,seems like it's back firing and it doens't want to rev freely,i've swapped around AFM's,and got another one to try out soon,though is this problem linked with the 02 sensor?

Thanks