I getting both side, have b20z in my obd1 integra, kept the same harness ND everything the same, just changed motor but I'm getting that I should get a crv ecu with jumper harness, others say I would be fine running my integra obd1 ecu, what's the right way? Maybe keep the integra ecu and tune it?? All opinion will be appreciated

 

The P75 ECU can run the B18A/B & B20B/Z, but you won't be able to utilize the knock sensor on the engine. You'll need the B20Z ECU for this, or a P72 chipped w/ proper basemap loaded to the chip.

 

What would the knock sensor really do though I don't have a cel

I'm not really advanced in the ecu and it being chipped and tuned area

and a 5speed crv ecu right, just to make sure

 

And a p72 obd1 ecu or p72 obd2 ecu, knowing p72 is a gsr ecu

 

OBD1 of course... lol. And no, you wont have a knock sensor CEL - because the ECU in your car doesn't search for it (no knock board). You're better off using the P75 that you already have.

 

They say since b20 is bigger then b18 the fuel ratio would be off, should I get a crv ecu and see how it acts or literally stick with my p75 and tune it later down the road

 

The o2 sensor will pick up and adjust for rich/lean condition and adjust fuel parameters; the difference between these two engines is very minimal. The cylinder heads of the two engines are nearly identical. Not to mention, the B20B/Z ECU will not directly plug into your vehicle. Stick with the P75.