OBD 1 and 2 When?

[e p slick]

On which year model did OBD 2 replace OBD 1?

Thanks - EPS

[Bill Verburg]

MY95 was the last for OBD1
MY96 was the first for OBD2

[rattlsnak]

Actually some cars had OBD2 in 95, but it was mandatory in 96.

[onboost]

Both those guys are correct!

[e p slick]

Thank you all.

EPS

[CrossT]

Interestingly, I have a 95 Jag xj6 that has ODB 2, but the Arizona DOT smog checkers don't use it. It goes on the treadmill just like my 89 3.2

todd
89 Targa

[signature65]

Just some trivia.....Porsche was the first company to ever use OBDI in the 80's

[Bill Verburg]

Originally Posted by rattlsnak

Actually some cars had OBD2 in 95, but it was mandatory in 96.

This being the Porsche 911 forum, I stand by what I stated.

Just because a car has an OBD2 plug doesn't make it OBD2 compliant. Yes, during the MY95 993 run they switched from the round OBD1 plug to the trapezoidal OBD2 plug, but that is all.

The most obvious differences between OBD1 and OBD2 wrt 993(aka911 for registration purposes) is
1)DME - 55pin for OBD1/88 pin for OBD2
2)wiring harness - OBD1/88 pin for OBD2
3) O sensor # & position - 1 centrally located pre cat sensor at the merge for the L/R banks for OBD1/2 pre and 2 post cat sensors for each bank(total of 4)

afaik the 1st use of OBD2 was for the RoW MY95 993tt which was N/A in the US untill MY96. All 993tt are OBD2. Only US '96 up 993na are OBD2, all RoW 993 na and US thru MY95 are OBD1.

That's why I chose a MY95 993 for my MY97 993RS engine to be transplanted into.

[kristoj]

Originally Posted by signature65

Just some trivia.....Porsche was the first company to ever use OBDI in the 80's

Just curious, which model year first had OBD I?

[Bill Verburg]

Originally Posted by kristoj

Just curious, which model year first had OBD I?

I don't know which was first but, '89 964 had an OBD1 port

[Steve@Rennsport]

Originally Posted by kristoj

Just curious, which model year first had OBD I?

That was 1995.

964's were simply OBD and used Porsche's proprietary system of monitoring and diagnostics.

[Bill Verburg]

Originally Posted by Steve@Rennsport

That was 1995.

964's were simply OBD and used Porsche's proprietary system of monitoring and diagnostics.

There is a need to differentiate OBD from the various Motronic version of engine management.

OBD - On board diagnostics has been used in various usually propriatary forms from ~1975. The first universal standard was promulgated by CARB(California Air Resources Board) ~1987. It specified that all cars sold in Ca. from MY88 on have some basic OBD capability. It wasn't specifically called OBD1 untill they came out w/ OBD2 for MY96 up.

The Porsche training manuals don't specificly refer to OBD1 or OBD2 but they do lump the 964 and 993 thru MY95 together along w/ the RoW 993 thru MY98, noting the diffference between the 993 version(DME 2.10.1 used for 993) and earlier version w/ unspecified DME version # used for 964 and the still earlier Motronic versions used on Carrera 3.2.

the '96 up use DME version is 5.2 and is used along w/ OBD2

[rattlsnak]

Originally Posted by rattlsnak

Actually some cars had OBD2 in 95, but it was mandatory in 96.

Originally Posted by Bill Verburg

This being the Porsche 911 forum, I stand by what I stated.

I agree, I was talking cars in general, as he didnt specify.

Bottom line, quickest way to tell is as Bill stated. Check how many O2 sensors it has.!