I'm having the same issues. standard ecu with new o2 sensor and still getting barely over 320kms.
I have a SAFCII. SHould I ask my mechanic to lean it out?
What is a safe AFR to run at for a stockish (SAFCII, FMIC, 11.5PSI Boost, 3" exhaust) R33? Please note that i'm from tas and we only have 95RON premium down here.
Oh yeah. The car seems to run really rich too. always popin/backfire noise when I change gear. I'm not getting any soot though.