What engines can you use in place of a D15Z4 without changing wiring ECU etc?

Directly swapping a D15Z4 engine without any wiring or ECU changes is extremely unlikely. The D15Z4 has a specific ECU and wiring harness tailored to its sensors and outputs. Other engines, even those within the same family (like other D-series engines), will have different sensors, different wiring layouts, and different fuel delivery systems.

To find a "drop-in" replacement, you would essentially need another D15Z4 engine. Even a different variant of the D15 (like a D15B) will require modifications.

While some engines *might* share similar physical dimensions, allowing them to fit in the engine bay, the electrical incompatibility makes it practically impossible for a true "no changes" swap. You'll always need to address wiring, ECU, and potentially other components like the throttle body or intake manifold.