stu/james ive got a query

i run one of your closed loop chips on t34.55lb etc
and when i put it on rolling road to check fueling etc it was lean high up the range,the fuel pressure was upped a bit to add more and it then went on to make good power(for the spec)
but now after this it no longer idles very well(hunts slightly up and down.
whats your opinion on this please