Lean idle and lean cruising

[T2ae]

As title states i am getting a average idle of 16.7 up to 18. Same with cruising is average 17.1. Seems to be fine when going wot. I have been fixing stuff on this car since i got it and this is about the last one! Got the ignition timing dead on 20deg as i am a auto. Some info on the car is a 1991 cefiro with a rb25det. Running a holset hx35,  full 3 in exhaust, front mount intercooler,  knock off greddy intake as i cant find any stamps, gtr 550cc injectors, blitz bov, tuned with rs enthalpy. Again all of this was done by previous owner and this may be something as simple as a new tune. Replaced plugs and gapped but didnt change anything. Verified fuel pressure at 2.8 bar (roughly 43psi) with the vac unplugged to the fpr.

[Ben C34]

Needs a proper tune  to fix it

[T2ae]

2 minutes ago, Ben C34 said:

Needs a proper tune  to fix it

What would you recommend? Is rs enthalpy bad?

[KiwiRS4T]

I have no experience of it - is it just a chip tune rather than an ECU? Any tune is only as good as its tuner but some hardware has many more options and possibilities than other. I lost interest at the point where users were installing an SAFC to "fine tune" the tune!

Looks like a Nistune chip would be an advance or if you can afford it a proper ECU such as a Link  or Haltech.