In maryland, if the car is not >= OBD2 (1995+ iirc) they sniff the
exhaust while the car is on the dyno.
If the car is > OBD2, they usually just plug it in and pull the codes
(no dyno run).

When I had my RX7, I used to fail the tests with the stock ECU for
being too rich.
After the megasquirt was installed (only change I made to the car), I
passed on the first try.

They never checked to see if my ECU was stock, only if I had a
complete emissions control system installed.

Sudhir

On Mon, Feb 2, 2009 at 11:48 AM, Allan Streib <streib@cs.indiana.edu> wrote:
> "pdooley" <psdooley@VERIZON.NET> said:
>
>> It is definitely not plug and play, and no good in emission checking states,
>> even though it would probably run cleaner than stock.
>
> So, not being familiar with what happens in an emissions check, do they
> actually look and verify that the ECU is stock?  I imagined they would
> just sniff the exhaust and (maybe) visually verify that the cat has not
> been removed.
>
> Allan
> --
> 1991 Vanagon GL
>