Gosh Darn Emmissions (90q20v)

[John Larson]

Ameer wrote:  You may have been able to squeak by in some cases, but that's
not the point. With readings that are that high over the limit, there must
be something wrong w/ the system. The auto engineers have designed all US
cars to meet emissions standards; and they're designed to run well below the
mandated limits, not squeaking by. Changing octane is not going to make
David's car pass. He already found that one out. When I failed my emissions,
it was not off by that much... only CO and Nox were a bit over the limit. As
soon as I changed the cat, the car passed easily... the change was dramatic.
All emissions were far below the maximum levels. I just think that if
something's broke, you should fix it...not try to squeeze by using fuel that
wasn't designed for that car.

-Ameer

You are, of course, right.  However, when the CO is well under the limit,
the O2 sensor and cat are new, and the tuneup stuff is a few hundred miles
old (I don't drive my car all that much), you do what you have to do to
bring the HCs down, and running a lower octane fuel is a known and
acceptable way to do that.  I don't recall what his numbers were, but my HCs
were only about 50ppm high, and then they weren't.  BTW, my car has in
excess of 250K miles on it.  IME, as an engine ages, even with good care,
it's less likely to give you the numbers you need to sit comfortably under
the limit.  John