I have an 88 honda crx hf with a good bit of modification done to the engine, exhaust, and fuel system. My engine is capable of 7000 rpm's but due to the stock HF computer the rev limiter I can only go to 5200 rpm's I had an MSD ignition, but it kept frying distributors so I removed it. I would like to know if I can replace the stock OBD1 HF ECU for an OBD 1 SI ECU without having to modify the wiring?The CRX HF comes from the factory with an OBD 1 ECU. The question is will any wiring change?The HF also comes with multi-port fuel injection. As far as my modifications are concerned:The cylinder head is ported, It has double valve springs, and titanium keepers,I have a 1.6L intake manifold and throttle body. Short ram cold air intake.Walbro 255 lph ( liter per hour ) fuel pump that gives me 62 psi of fuel at the fuel rail. I also have a full coilover suspension and 17 inch AXIS alloy racing wheels.I also have D/C headers and 2.25inch exhaust all the back to to the muffler, which is 2.5 inches in and 3.5 inches out.I appreciate the info. Will the Si Transmission bolt up to the 1.5L motor?Are the older Si computers OBD 0 or are all SI computers OBD 1 ?Is the gearing the same in the older SI tranny as the 92 and up?