check injection and check esp

Last night my car told me to check the injection and the esp and when it got to 3000 revs it died down to about 2500 then back to 3000 and so on. But if I switch it off then back on the problem goes away. Rs tuning did remap it on Wednesday but they seem to have a good reputation.
Any ideas
 
Try the throttle position sensor cable is in correctly?? seems like the ECU is being confused by a bad signal to me. They may have messed with the throttle body. I started my car up with out the TB sensor plugged in by mistake ooops and you get the same fault coming up in the dash. Something like injection fault ?
 
This happened to me a while back, started it 30 times.. Had to get a train to work. Got home that night. Never had a problem since touch wood.