I'm Gonna Put OBD II On My Nissan Skyline GT-R

Nissan Skyline GT-R R34

2018-2019 edit. I have a functioning OBD II system that works on an R34 GT-R. In the process of getting EPA and California certification and testing done. It was a struggle, but it works properly. 


I am getting this question at least a couple times a month. Any car 1996 or newer in the US, needs to have a functioning OBD II system for an ICI to bring the vehicle into compliance. Are you going to, just put OBD II on your Skyline GT-R? No you aren't. Install an OBD II ECU, and then think that this makes the car OBD II compliant? No it doesn't.   People have questions about vehicles that are newer than 21 years old, that they want to import under Show or Display.  The problem with that, well read on.

First off, you need a bit of a primer on OBD II. OBD is OnBoardDiagnostics.  The II means version 2, the second. http://www.obdii.com/background.html

"OBD-II, a new standard introduced in the mid-'90s, provides almost complete engine control and also monitors parts of the chassis, body and accessory devices, as well as the diagnostic control network of the car."

OBD II connector

The key part about that is OBD II is not only the engine, but parts of the chassis, body and accessory devices. It is a tip to tail emissions monitoring system. Not a single part. Not an ECU. Not a catalytic converter. Not an oxygen sensor. Not an evap cannister. Its all those things, plus the system that makes sure all those things are functioning correctly.

So why do we have OBD II?  Blame Los Angeles. Blame California.

To combat its smog problem in the LA basin, the State of California started requiring emission control systems on 1966 model cars. The federal government extended these controls nationwide in 1968.

Congress passed the Clean Air Act in 1970 and established the Environmental Protection Agency (EPA). This started a series of graduated emission standards and requirements for maintenance of vehicles for extended periods of time. To meet these standards, manufacturers turned to electronically controlled fuel feed and ignition systems. Sensors measured engine performance and adjusted the systems to provide minimum pollution. These sensors were also accessed to provide early diagnostic assistance.

At first there were few standards and each manufacturer had their own systems and signals. In 1988, the Society of Automotive Engineers (SAE) set a standard connector plug and set of diagnostic test signals. The EPA adapted most of their standards from the SAE on-board diagnostic programs and recommendations. OBD-II is an expanded set of standards and practices developed by SAE and adopted by the EPA and CARB (California Air Resources Board) for implementation by January 1, 1996.

So the whole purpose of OBD II is to minimize smog emissions, in LA. LA expanded to federal(EPA) .

All cars built since January 1, 1996 have OBD-II systems. Manufacturers started incorporating OBD-II in various models as early as 1994. Some early OBD-II cars were not 100% compliant. <Click here> to see the dates OBD-II started being included on specific makes and models.

Not ALL cars. All cars originally sold in the US from January 1, 1996 have OBD II systems.  Cars produced for markets other than the US don't have OBD II. Japanese cars, European cars unless they were made for the US, don't have OBD II. In fact, Japan didn't pick up similar standards until 2003, which is why the Toyota Supra, Nissan Skyline GT-R, Mazda RX-7, Nissan S15 all stopped being sold in 2002...

NISMO 400R

Then the main question becomes, can you "put" an OBD II system on a vehicle that never came with it?  The answer is of course, sure you can. However, in order to develop a properly functioning system, and get it certified, it is very expensive. In fact many OEM's had OBD II systems that were missing some major components from 1996-2000. They were still trying to make their systems work. So making an engine, like an RB26 which has its roots in the mid 80's, with never any emissions in its path, is difficult. Even something like EGR(exhaust gas recirculation), which help lower NOx emissions, is simply missing on the RB26. No air pump, no EGR make FTP testing difficult.

OBD II is a deal breaker. Unless you can foot a bill in the $250k+ range(we did) to develop a system, you should just keep dreaming, and playing the lottery. Give me a buzz when you hit your numbers. Even once you get the system working, expect the EPA, and the ARB if you are in California to check and recheck the system until they are satisfied it works correctly.

FTP testing an R33 GT-R

More OBD II Links and Information.
OBD II Technical Library.

NISMO 400R