how can i tell what obd my engine is?

 

Are you concerned with the engine specifically or the engine computer? The only reason I ask is because this is the EMS and EMS Tuning Forum. The engine itself has minor differences between OBDs. The main difference is the distributor plugs. Another difference is the location of the radiator fan switch. Other than that if it is a USDM engine you can look at the block's ID stamp, but it depends on which engine platform you have. The year is stamped on the cylinder head too, so that helps, but there are more depending on platform.

Basically you are asking a loaded question since there are variations of different styles between platforms. I can assume you are talking about a H, B, or D series but maybe you aren't. Even then, are you talking VTEC, NON-VTEC, or even the market it was sold in matters. It REALLY helps to not post extremely vague loaded questions. We need pictures or WAY more detail and not some BS one liner.

 

the best I got:
if the electrical connectors are white, it might be OBD-0. Maybe.

 

Obd0 has a resistor (looks like an aluminum heat sink) on the driver side bolted to the firewall. It also has round plugs on the distributor, and a 1 wire o2 sensor on the exhaust manifold. Also has a oil temp plug on the rear of the engine.
Obd 1 has no resistor box, rectangle plugs on the distributor, a 4 wire o2 sensor on the exhaust pipe in front of the cat, and a temp sensor plug on the thermostat housing in place of the oil temp sensor on obd0. Also more likely to have abs.
Obd2 has a plug under your dash you can use for a code reader, rather than having to jump a wire and count blinking lights. Obd2 typically has 2 o2 sensors, one on the back of the cat. It also has vtec capability.

 

For what it's worth - OBD1, OBD2a and OBD2b Accords and Preludes also have the resistor box.

Best way to tell what OBD your engine is as stated above, Use the engine manufacture date. The block and head will have the last 2 digits of the year it was manufactured.

This is a pretty basic list of years and the corresponding OBD for USDM engines. Some chassis used OBD1 before others.
88-90 - OBD0
91-95 OBD1 (Accords went OBD1 in 1990)
96-97 OBD2a
98+ OBD2b

this is just a general rule of thumb.

 

 

OK, so even here we see that there are some other differences between chassis. The 98 Accords were OBD2B and it was used up until 02.

 

Probably the first to be released as a 1998.5 production year model, that used OBD2B.

 

May have been..... although all 6th Gen Accords are OBD2B


Also, isn't OBDII still used today? There are different OBDII protocols used for signaling is the difference. Up til 08, wasn't there something about making everyone use one standard for US vehicles - ISO 15765-4. It's been a while since I paid any attention to what protocol was used. I just plug my scan tool in and read the diagnostics and live data!....

 

also to mention 90-91 preludes that came with the b21 were obd1, while the 90-91 preludes with the b20 are obd0, and all 96-01 preludes are obd2a

 

My late 1997 production year CRV that was sold as a 1998 model was OBD2B. I think his generalization was more accurate. In any case, who cares?

For one, the OP has never even responded. And two, there are oddities in all manufacturers and is best to just not be lazy and take a look at the ECU to end any and all confusion.

Take the DA Integras for instance or even CRVs. Honda isn't very consistent as everyone likes to think they are.