OBD1 and OBD2?? whats the difference?

astroxtc · Post by **astroxtc** » February 15, 2005

so what is the difference between the OBD1 and OBD2 ecu's??

munster · Post by **munster** » February 15, 2005

The main difference other than plug differences, etc. is that obd2 has two O2 sensors. The ecu pulls information from the first sensor and checks it with the second sensor. Pretty much to see if the catalytic converter has failed or is missing. obd2 also has a taddle tell system.

Hercules · Post by **Hercules** » February 15, 2005

yes and and there are different kinds of obd 2's like 96-98 is obd2a and 99-01 is obd2b someone correct me if i'm wrong

munster · Post by **munster** » February 15, 2005

Dc2gsr95 wrote:yes and and there are different kinds of obd 2's like 96-98 is obd2a and 99-01 is obd2b someone correct me if i'm wrong

That seems right unless I'm wrong. I thought 2b was up to 00 and 01 and up has some other version of obd2.

phan · Post by **phan** » February 16, 2005

i'm with munster, i'm sure 00+ is 2b.

jdmhatch21 · Post by **jdmhatch21** » February 17, 2005

also ob2 has to be hooked up to a computer to read codes. No more flash codes. OBD2B is 00+.

astroxtc · Post by **astroxtc** » February 18, 2005

so what is perfurred? better?

Post by **tenchu** » April 16, 2005

Neither is really better. The only advantage to OBD2 over OBD1 as far as I know is the fact that every car has a univeral plug, weather is GM, FORD, HONDA, or NISSAN, the government made it manditory that all cars had the same diagnostics plug to make it easier on mechanics. Cars that come with OBD2 are a little pickier usually, ie: if you remove a catalytic converter in your car it will throw a code to your ECU, and usually toss the C.E.L. and the emissions testers will be able to see that when they plug it in, though there are ways to bypass that also (like we did in the WRX).

Post by **Sean @ NDF** » April 17, 2005

Munster pretty much explained it in his first answer...

OBD = On Board Diagnostics, aka your emissions controller if you will...

I converted my 00 si to obd I because of the ease of tuning an I car over the stock II. But it is illegal if you live in my state

munster · Post by **munster** » April 17, 2005

I converted mine to obd1.

It's not illegal in PA...yet.