f**k, do I need to spoon feed you through your whole build? *1 R33 RB25DET Skyline The original R33 RB25DET ECU cannot be used with a Nistune board (a) We recommend sourcing an R32 Skyline ECU which is compatible. These ECUs require little modification and reuse existing O2 sensor, knock sensor and TPS sensor (TPS idle switch is replaced by soft switch in firmware) and come with RB25 base maps and are the recommended ECU for tuning Nissan ECU Part numbers on front of R32 ECU case: 23710-04Uxx: Uses spare LED output to run VCT 23710-11Uxx: Uses fuel pump idle control output to run VCT VCT modification information here Note: Series 2 there is no IACV (Air cond output idle up control valve) output on these ECUs. Recommend wiring IACV solenoid directly to the AC relay (same as Series 1) Note: Manual transmission models only supported. If using an automoatic transmission model R33 Skyline then reportedly the R32 Skyline automatic transmission control module will work (b) Alternative option is the Z32 300ZX VG30DE (1990-1992) / Z32 300ZX VG30DETT (1990-1993) ECU These ECUs use different knock sensors which will need to be disabled, some other modification including connecting both O2 sensors together and removing fuel temp input to the ECU are required. There are mixed reports with tuning these particular ECUs so we recommend using the R32 ECU where possible. Modification information here Part number listing information here https://www.nistune.com/equipment-products-type2.php