import_tuner13

Ive got this posted in the swap forum too...im that desperate lol! searched everywhere. I'm going to the pros now. Got a 1996 accord with a Jdm h22a in it. . the car and engine are obd2. Been running a obd1 ecu with a harness for years, everything runs beautiful. Due to a need to pass "emissions" in my state, I acquired a p13-a12 1996 prelude ecu, the exact one you need(rare), can't remember the exact ecu code. According to EVERY swap post I read, you need to switch pins a6 and a11 on the stock harness to have the ecu work correctly. So I did. Despite everywhere saying pin a11 was for the injectors. So I swapped the pins, and, instant CEL. Same if I put the pins back the other way. Vtec failure, o2 heat failure. I'm stumped. Car idles like crap, wants to die. Anyone? Please?

holmesnmanny

No, you do not swap those pins on a car that was already obd2 so put them back.

Now for the bad news. Then you need to get a '96 prelude si vtec oil pump assembly. Then you need the crank timing pulley and front balancer shaft pulley as well as the for the bolts that secure the crank and fluctuation sensor bolts from a '96 si vtec car(im guessin two bolts each(4 total) without looking it up at the moment) and you will need to install that oil pump assembly onto that block after pulling the oil pan. Plug in the sensors and you should be good to go.

(btw if you are obd1 right now you did need to adjust the ignition timing, not sure if you did that yet) this is irrelevant when you switch to obd2 but you will need to swap back to the obd2 distributor

good luck and please report back

import_tuner13

I think I need to clarify. I was running an obd1 chipped and socketed ecu from speed innovations. They sold a sub harness that converted all the correct wiring to that of the chipped/socketed ecu. I already had the dizzy stuff and oil pump done to make it ready for obd2. And now, knowing I don't need to switch those wires is a huge help. I have 4 CEL codes, 3 pertaining to Vtec and one pertaining to an 02 heater failure. The Vtec has got to be that I don't have a Vtec oil pressure switch on my obd2 jdm h22a engine. Bypass it, or get a switch? Secondly, would the Vtec being out and the o2 heater code cause the car to run like crap? Am I over thinking this? Could I just have a bad o2 sensor?

holmesnmanny

The car will run in limp mode with a code 22 thrown. The a6 pin is heater circuit so thats likely cause of the pin swap.

Just get the vtec pressure switch.

import_tuner13

Thanks so much for the help so far. Got the Vtec cell gone, still have codes p0135 and po155. Primary 02 sensor heater. Replaced o2 sensor. Same codes. Traced continuity from ecu to o2 sensor. 12 volts. Tapped into secondary o2 sensor, seems to be self grounding as voltage reading all over the place, primary o2 sensor sits at 12 volts. No change in voltage at all. What am I missing? !?

holmesnmanny

Did you put the two swapped pins back ?

import_tuner13

Yes. I did. Potentially a bad ecu? Did I destroy a sensor by swapping the pins? Both myself and my mechanic friend are at our wits end lol

import_tuner13

Update: I'm keeping this thread going for future idiots just like myself. I'm under the assumption I damaged the ecu by swapping those pins, so I'm sending it out to hamotorsports in cali for ecu repair. Round trip cost including repair is approximately 75$ assuming I didn't do major damage. :/ I wonder if a bad o2 reading would cause the car to bog down like crazy too. We will find out I guess.

holmesnmanny

Its gotta be the connection or however you're swapping the pins.

import_tuner13

You'd think so, but I think I may have fried the ecu portion when I swapped those wires. I tested wires a5 and a6 (primary and secondary o2 heater). When the key is in on position they are both at 12v. When the car is started, the "good" o2 sensor is grounding itself fine and voltage reading all over the place, the "bad" o2 sensor is sitting at a constant 12v. So it's not grounding, hence the heater is not heating. I assume it uses the same ground as the good sensor? I already replaced the o2 sensor once, (denso to denso). Traced wire to o2 sensor, heater is getting power. Would code p0135 and p0155 cause the car to run like crap?

holmesnmanny

No. It would simply run predetermined fuel map values as soon as the code is thrown.

Did it run fine again when you put the obd1 ecu back in?

import_tuner13

Yes. Runs fine with the obd1 ecu. Just went out and started it, ran both ecus. Obd1 ecu runs fine, obd2 ecu throws the codes and bogs hard when I give it gas.