Hey everyone, I’m hoping to get some advice on a few problems I’m facing with my ’96 EK Hatch. It’s a bit of a Frankenstein build, and I’m running into some snags. The car has a B18C block with a B16 PR3-2 head, a ’00 Si transmission, and a bunch of aftermarket parts like a Skunk2 intake manifold, Skunk2 cam gears, JG Edlebrock 65mm throttle body, short ram CAI with K&N filter, RC 550cc fuel injectors, AEM fuel rail/regulator, MSD spark plug wires, DC Sports 4-2-1 race header (no cat), A’pexi WS2 exhaust, and an OBD1 P28 ECU with Hondata S100.
I’m really scratching my head about a few things, so any help would be massively appreciated.
OBD Confusion: OBD1 or OBD2?
First off, the engine harness is the original ’96 DX non-VTEC one. I’m not even sure if the engine itself was originally OBD1 or OBD2. The head and transmission seem to be from a 99-00 Si, and the block is stamped B18C. The trans is definitely a 2000 Si, and the head has PR3-2 on it. Right now, I’ve got a P28 ECU which is OBD1, hooked up with an OBD2 to OBD1 conversion harness adapter.
So, what am I even classified as, OBD1 or OBD2? It feels like the car is split right down the middle, half OBD1 and half OBD2. I’m trying to figure out what parts are going to be compatible with this OBD1 ECU setup. It’s all a bit confusing to wrap my head around.
Oxygen Sensor and Code 41: Aftermarket Header Problems?
The second big issue is the O2 sensor. From day one, the car’s had a CEL. I pulled the code and it’s Code 41: Primary oxygen sensor heater. So, I figured it was a simple fix and bought a universal Bosch sensor. I wired it in, but the code is still popping up. I wired it like this: the two original equipment (OE) black wires (heater) to the two Bosch white wires, the OE white wire (signal) to the Bosch black wire, and the OE green wire (signal ground) to the Bosch gray wire. I really hope I got that right! I was told the heater wires don’t matter which way they are connected as long as the colors match up.
The car runs exactly the same whether the sensor is plugged in or not, which makes me think it’s just not working at all. The engine harness has two plugs for both a front and rear O2 sensor, but I’m only using the front O2 plug because an OBD1 ECU doesn’t use a rear O2 sensor, right? Could this B18 Obdii Aftermarket Header O2 Sensor issue be related to the header itself? Maybe it needs a different type of sensor or wiring?
Speedometer Not Working
Problem number three is the speedometer – it’s completely dead. I’ve checked all the fuses and they’re good. I also checked the wiring to the Vehicle Speed Sensor (VSS), and that seems okay too. I’m wondering if the VSS sensor itself is just bad. Wouldn’t I usually get a code if the VSS was faulty? I guess the next step is to just swap out the sensor and see if that fixes it.
Engine Harness Replacement: OBD1 or OBD2 Again?
Fourth problem, and I know this is getting long, is the engine harness. I’m seriously thinking about just swapping it out for a 96-98 EX harness or a 99-00 Si harness. The previous owner didn’t seem to do a great job with the current one. Almost every sensor looks like it’s been spliced into the original harness. Just yesterday, the car wouldn’t even start because a wire to one of the fuel injectors came loose. It took me a good hour to find that problem!
Alternatively, could I use a 92-95 Civic OBD1 harness? I’m not sure about compatibility since, like I said, I’m still confused about whether the engine is more OBD1 or OBD2. How can I even figure that out for sure? This car is truly a Frankenstein creation!
Injector Resistor Box: Necessary?
One more thing – there’s an injector resistor box installed. Do I actually need this? I’m assuming I do, but is there a way to swap out the injectors to get rid of it? The box is just dangling behind the head and it looks messy. Just another thing I’d like to clean up if possible.
Hopefully, I haven’t totally confused everyone with all these problems. If anyone has any thoughts on any of this, please chime in. I really need all the help I can get!
