Okay so I'm going to try and do a quick TLDR of what the issue is and what I've done as far as troubleshooting goes.

​​​​​​... Doing things one shouldn't do with a d17 as they are notoriously weak haha, the motor blew. Swapped motor on a saturday 2 weeks ago. Has been running fine since, until 2 days ago. Started to misfire, once or twice every time I drove it, then would be fine for the rest of the day. Finally gave up and had a constant misfire on cylinder 4 and has been persistent ever since. Troubleshooting so far
- installed 4 new spark plugs
​​​​​​- swapped coils between cylinders, no change always cylinder 4
- verified spark by grounding spark plug threads to chassis while idling, spark is present.
- checked resistance on all 4 fuel Injectors, 3 read 12ohm as they should within spec, the one for cylinder 4 was perminantly closed (infinite ohm reading) and thus was bad and was replaced, however this did not resolve the issue unfortunately
- swapped fuel injectors around, cleaned fuel rail, no change still only misfire on cyl4.
- did compression test, results were good reading 180-170-170-180
Now I was a little confused so went back to see what I may have missed.

- Checked voltages at fuel injector connectors. When car is in on position, all 4 injectors read 12.5v. when car is running, the 3 good connectors read 0.7v as normal, connector for cyl4 is still reading full battery voltage (aprox 14v at this point).. So it basically is giving injector for cylinder 4 over voltage and causing it to just stick closed. Thought it might be a ground issue so I took everything back apart and grinded / sanded down every single ground point, no change.

I then checked ohm resistance between ground pins of the each of the 3 good connectors and the chassis ground. 3 good ones read aprox 425 ohm resistance (all within one ohm of each other), connector for cyl 4 reading 305 ohm.

This indicates a wiring issue

I disassembled the wiring harness and made a small nic in the wire a few inches down the line and repeated this test, same result. That rules out the actual connector being bad. A visual inspection of the rest of the harness all the way to the firewall reveals no potential issue.

From here, as far as I can gather from fellow Honda enthusiasts around my area, mechanical people I know and these forums, the next step would be an ecu swap & reflash

I am here writing this asking anyone who is willing to read the novel I just posted lol, if I have missed or overlooked ANYTHING, or if more troubleshooting is needed somewheres that I am not aware of? There should be no relay for the fuel injectors as far as I know for this vehicle, simply a fuse. And they should go directly into the ecu?

Absolutely any help would be appreciated. This is currently my daily driver and I would absolutely love to be back on the road by Monday if at all possible, and not have screwed myself. Thank you!!