PHiZ

well the problem I am seeing with OBD2 is that, the ecu uses sensor input to adjust your fuel trim, to try and adjust it to stoich (well honestly in a honda, a little rich). So running on bad o2 sensors could totally negate the benefits of having the high flow cat... Running with the sensor out of the pipe, again it's going to screw with the OBD2 using sensor inputs to run the car properly.

OBD2 learns, and has a memory, reset your ecu, see if it runs better for a day or two, until it relearns it's naughty behavior.

I just unplug my ECU for a couple minutes, but you can just pull the ECU fuse, or pull the hot battery terminal for a couple of minutes.

Mind you, method 2 and 3 from above will reset a factory radio, and you'll need the code to unlock it.

-PHiZ

blacklude97

im gonna be getting the obd2 obd1 conv. with a p72 gsr ecu , i hope this solves the problem

PHiZ

the 00 SI has a B16? You don't need a GSR ecu, that is the most expensive ECU on the market, because it has the IAB control circuitry.
You're probably better off with a P28, and conversion harness, I have a guy that sources these, internally converted just like hondata.

-PHiZ

Do some searches around here and honda-tech, this is not an uncommon problem, see what other solution people have encountered.

Also, you'll have to disable knock sensor in code, for your application.

Just change the byte at 60E7 to 00

blacklude97

ohh, would the gsr ecu be good?? i got it for a fairly good price.

crxb16er

the gsr ecu is good but the si ecu is better.

MrFatbooty

The oxygen sensor works on a chemical reaction between the electrode and oxygen in the exhaust gas that is sent as a voltage signal to the ECU. The ECU then extrapolates the a/f ratio from that voltage. It does not measure pressure.

Chipping the ECU is like sawing your arm off just because you break it. Better to put a cast on the arm.
Factory Honda oxygen sensors are narrow-band. They have a very limited range of operation, which means that most of the time the ECU is running in open-loop (i.e. not using o2 sensor data) mode. When it does switch to closed-loop it uses o2 sensor feedback to modify the fuel trim, but there is no difference in the way OBD-1, OBD-2 or non-OBD ECUs do this.

Secondly, the "memory" function is very limited and basically the only area its effects are actually noticeable is ignition timing, where if you advance the timing by spinning the distributor the computer will eventually figure it out and compensate.

Finally, since this is a turbo'd car it doesn't really matter what generation of ECU there is. Once the code is fixed by PROPERLY DIAGNOSING THE OXYGEN SENSOR PROBLEM then it will run fine. If you want to tune the car then ditch your rising-rate fuel pressure regulator, get 450 cc/min fuel injectors and an A'PEXi V-AFC.

Switching to OBD1 just so you can run a chip that isn't even tailored to your setup is pretty pointless--the V-AFC combined with larger injectors can be tuned on a dyno that has a wideband o2 sensor hookup and will yield far better results.

crxb16er

:thumbup: i completely agree, chipping ur ecu is just putting in someone elses idea of power on ur ecu and u lock in their fuel maps, get ur own way of tuning and adjust accordingly to ur engines capability

blacklude97

i dont think i can fix the code because of obd2 , thats why im changing to obd1 and then im gonna tune my vafc

MrFatbooty

OBD2 has nothing to do with your code.

blacklude97

well, because of obd2 it senses the problem and is trying to fix it , which is trying to make me run lean. with obd1 it will sense the problem and give me a cel , but it wont try to fix it.