What is a lev versus a ulev engine?

My "check engine idiot light" came on on my 02 accord and when
reading the owners manual for a possible solution, it stated that on a
ulev model to tighten the gas cap. On a lev model, bring it in for a
check. Is this leaded gas versus unleaded? Anyhow, I went outside and
tightened the gas cap. It further states it might take 3 trips to
clear the light if it was a loose cap....Any help? Thanks...Mike

 

On the underside of your hood you should find an EPA sticker that will tell
you if you have a Low Emissions Vehicle, or an Ultra-Low Emissions Vehicle.

 

LEV = Low Emission Vehicle
ULEV = Ultra Low Emission Vehicle
SULEV = Super Ultra Low Emission Vehicle

There is also:
TLEV = Transitional Low Emission Vehicle.

All these designations are determined by the actual level of certain
chemicals emitted by the engine in official tests.

Any vehicle that will turn on the MIL due to an insufficiently tightened
gas cap will have OBD-II engine controls. It may or may not be a ULEV. Some
vehicles for some markets may still have the OBD-I system, which does not
turn on the light if the gas cap is not tightened properly. If you're in
the US, you have OBD-II. The light should go off soon.

Leaded gas has not been sold in the US since about 1980, and not in Canada
since about 1988 or so.

 

Yep. There is also:
ZEV = Zero Emission Vehicle (all eletrics like the EV1)
PZEV = Partial Zero Emission Vehicle (a CA designation to give
credits to companies when it became clear that none would hit the
CA mandated ZEV req'ts). These cars are SULEV plus essentially
zero evap emissions and are emissions-warrantied for
15yr/150,000mi.

Yep, specifically CO, NOx (NO+NO2), non-Methane hydrocarbons.

Basically what is happening is that if your gas cap is loose, some
gasoline vapors may be released. To meet the more stringent
emissions standards, this is a no-no. (Speaking generically,
not specific to Accord) ...so the on-board sensors flag this and
the check-engine light comes on. It'll also come on for a host of
other things. First check is the simple one: tighten the gas cap.

 

(Dave) melodiously murmured in

ZEV *only* if you don't count the emissions from the construction,
maintenance and operation of those electricity generating plants that are
needed to support "ZEV" vehicles.

Touché! There are reasons why California is known as La-La-Land. Lovely
though the place is.

But none of the aldehydes or other deadly gases produced by those emission-
control devices themselves.

Too bad those same emissions regs ended up producing fuelling nozzles that
sometimes result in actual liquid spillage due to those dumb bellows-type
vapor traps.