I was wondering if putting a head from a D15 engine onto a D16 engine would be possible without having to re-tune the ECU. I ask this because while I have heard of conversion harnesses to allow one to use an OBD-I ECU with an OBD-II engine, I never have heard of anyone using an OBD-II ECU with an OBD-I head. My idea would be to use a D15Z1 head onto a D17A6 bottom end with an ECU from a '96 Civic but have been trying to think of potential problems with this setup. Does the D15Z1 support more lean or less lean fuel mixtures than the D16Y5 or D17A6?

 

What the hell did I just read???

Are you using all weird *** UKDM parts? We don't have d16y5's or d17a6's in North America iirc.

 

noob, D16Y5 is the '96-'00 Civic HX engine and the D17A6 is the HX engine from the '01-'05 Civic HX....