Hey there,
I have a 99 civic with a d16y8 recently swapped in, running an obd2a p2p ecu with an a-to-b jumper harness.
The car is running and driving fine, but it is throwing two codes, 20(ELD) and 41(o2 sensor heater), which concerns me, because I need to pass emissions within the next 8 days.
Any idea of anything I should try to get rid of the codes?
Also, potentially unrelated though i'm not sure, the spedometer reads 20mph about 70% of the time, whether you're going 100 or you're stopped.
Thanks!

 

You have an electrical issue. Better get to it.

 

Any idea where to start? I thought it could be alternator related. I swapped a y7 distributor onto the y8. The battery reads about 13.3 with the car turned on (not started), and about 14.4 running.
Also, more specifically, the codes are p1298 and p0135. Fuse 15 is not blown (I've heard that that could be related to the codes). Could it be related to grounds?
I also fixed the speedometer by fixing some cold solder joints on the gauge cluster, so that was not related to the codes. I could try swapping the alternator from a spare y7 to the y8 in the car.

 

ELD codes are often spurious.

Did you inspect the wires associated with the fuse 15 problem? You can still have frayed wires and opens or shorts even if the fuse does not blow.

The live wires (yellow and black) to the O2 sensors should be battery voltage with the key on. If not, check and repair the harness. If that is OK unplug the sensors and measure the resistance of their heater section (the two wires that are the same color, usually black). It should be 10 to 40 ohms. If that is open circuit, replace sensor. Finally, the other wire from the heater has to have continuity back to the ECU.