I'm taking my car in Tuesday for the 2 year emissions test for the state of Maryland. I passed the one 2 years ago with plenty of wiggle room.

Car is a '95 Geo Metro with 163,000 miles. It uses about a quart of oil every 1000 miles. I don't see smoke coming out of my tail pipe, and the MPG is around 45 city 50 highway. I'm pretty sure I will pass. I recently used some Fuel Injector cleaner, and the car runs very smoothly.

Do any of you have experience with failing emissions tests and what you had to do to fix it? Do you know anything to do to make your chances of passing as good as possible? Thanks.

Instead of worrying, I'd wait to see the results and go from there. You could be dong all this hand wringing for nothing.

Much agreed. Take the test. If you fail, come back with results and I'll tell you exactly what you need to pass.

-MechanicMatt

This idea may only apply to compression ignition engines (diesel), but an oil change, if you're due for one, won't hurt. Changing the air filter, if it's due, also can't hurt.

HOORAY I passed.

Hydrocarbons .5648 GPM maximum allowed .9000 GPM

Carbon Monoxide 3.2519 GPM maximum allowed 20.0000 GPM

Oxides of Nitrogen .3275 GPM maximum allowed 2.1000 GPM

All those look good except for hydrocarbons, which is a little high.

What could that mean?

HOORAY I passed.

Hydrocarbons .5648 GPM maximum allowed .9000 GPM

Carbon Monoxide 3.2519 GPM maximum allowed 20.0000 GPM

Oxides of Nitrogen .3275 GPM maximum allowed 2.1000 GPM

All those look good except for hydrocarbons, which is a little high.

What could that mean?

Car looks healthy. Your catalytic converter is apparently in decent shape (HC and NOx are in check), and your EGR system is functioning very well (NOx output is quite low). Now don't get me wrong, there are a lot of possible reasons why your HC's are a slightly raised. But it would not be unreasonable to think that your oil consumption could have something to do with it, if in fact you are burning it, and not leaking it. Recall that gasoline (HC) is simply (well not simply, but nonetheless) a more refined version of motor oil.

-MechanicMatt

My metro gets by the AZ test(not hard at all you could be billowing black smoke all day and still pass) but i am almost below the tests sensitivity lvls lol