"DavidK" > wrote in
. com:

> After having passed the California smog check for 2 tests (4 years) in
> a row, my stock '94 Del Sol ("S" model with 1.5L engine) failed today.
> :-( It's the first time I've ever had any car fail the Smog Check, in
> 20 years of living in California.



Post ALL your numbers, including the limits for your area.



>
> I have never made any modifications to the engine, and I take it in
> for regular maintenance according to the maintenance schedule. It has
> been about 6500 miles since its last oil change, and I don't use any
> pour-in fuel additives. It is running normally with no noticeable
> engine problems.
>
> Here in California the DMV has recently made the Smog Check test more
> sophisticated, using a 'dynamometer' (treadmill) to test the car under
> load. They test the car at a simulated 15mph and at 25mph. They also
> added a NOX (nitrous oxide) emissions check, and that's the one that
> my car failed, but only at 15mph.



Post ALL your numbers, including the limits for your area.



>
> As for my other emissions test results, my Del Sol had extremely low
> CO2, O2, HC and CO emissions at both 15mph and 25mph, but failed the
> Nitrous Oxide (NOX) test at 15mph. In fact, the NOX emission was
> about 3 times higher at 15mph than at 25mph, which seems
> counter-intuitive. I had driven the car at least 15 miles before
> arriving at the test facility, so it was well warmed-up.



Post ALL your numbers, including the limits for your area.

If you were extremely low in HC and CO, that suggests either you're running
hot, timing is too far advanced, or your EGR system is not working
correctly.

You cannot be extremely low in CO2 if you were extremely low in HC and CO.
If you were very low in HC and CO, that means the cat has managed to bind
its stored oxygen to the CO and HCs to make them into CO2 and water. So CO2
ought to be HIGH.


--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/