I may not be of help. I have had 2 Z's with Ash chips...the 2+2 was no problem. I restored a TT and originally was mild mods 500's?nismo 550's (which started to fail) so I went to DeatschWerks 740's for future upgrades. I had Ash send me a Deats chip....yes it runs rich. Idle I believe is not the problem, I believe this is close loop??? But I have recently gone NIStune and dyno the Z. I am running real rich, downloaded another friends Z with Nismo program to compare, I see them both as rich. I don't know if this is done to be safe....but it does affect performenace. I now have an LC-1 to get real time A/F ratios. tuning is a learning experience...comparing the fuel maps both are rich, I will also probably play with the timing maps later....but with out a burner or piggyback you are stuck with their program.
