So I have an em1 with a JDM b16a swap. It won't pass emissions due to this. I'm gonna buy the usdm 99-00 civic si obd2b p2t ecu. I'm gonna perform the FF Squad CFK Bypass trick. I'm buying a used ecu, and was wondering if there were any tricks to make sure the ecu works properly? BTW, I'm bringing my car to the purchase. Any help is much appreciated. Thanks everyone!

 

Are you currently running the jdm ecu? the usdm ecu will also look for a vtec pressure switch, knock sensor, and i believe 2nd o2 sensor and may throw codes

 

Yes, currently running the JDM ecu. I'm new to all this and am learning new things. I had no idea that there were these possible codes that might show also. Any resolutions, or ideas?

 

there's going to be quite a few things the 99 to 2000 ECU looks for being that its obd2.
Secondary 02 sensor will need to be connected and in the exhaust. I've seen people use those oxygen sensor simulators which are basically small extensions for the o2 sensor boss to give the sensor just the correct amount of exhaust to mimic a functioning catalytic converter.

Sounds like you already got the fix for the CKF sensor by jumping it at the ecu at the correct pin.
The vtec pressure switch is an easy fix. Swap on a US spec solenoid with the switch.
The ecu will have to be able to communicate through the obd2 port, so once you get it installed, you should be able to check codes just like a regular 99 em1. if there's no check engine light and the car is running good you're on your way to being set. I forgot the requirements on the obd2 emissions readiness test but it likely involves a couple drive cycles and warm-up cycles meaning drive it for a week or so to ensure they're set.
and for some reason I want to think the EVAP system is also monitored meaning that your carbon canister and all the vapor lines and purge valve to be connected and functioning but I could be wrong...

And you'll need stock injectors too if you don't have them already. That's all I can think of at the moment.

 

Get a code reader. When you get the ecu, plug it into your car before buying it.
Turn the key on and read the codes with your code reader (that plugs into the obd2 port) .
You should see the fault codes just mentioned. Once the faults are recorded, start the car. It should start and idle since none of those faults are related to engine operation. Just emissions fault codes. Someone correct me if I'm wrong.

 

is your engine obd1 or 2? are you using the factory em1 harness?

 

Thanks everybody for the help.

 

To be honest, I'm not sure. From my observations, I think I'm running the stock si harness with a jumper harness. Any way I can make sure? And I think my engine is obd1, but idk?

 

Does the distributor have 1 Or 2 connectors? 1 is obd2.
2 connectors is obd1.

You most likely have the factory engine harness unless someone did it the harder longer way.