Getting my 19 year old Integra to pass smog

My car needs a passing smog test before getting my California registration stickers. Now, it has always passed in the past, but the levels were quite close to the passing cut off.

Are there any little things I can do prior to bringing it in to give it a better chance?

I read up on some suggestions that were given about another posters '98 Toyota, and some mention taking the car for a 20 mile/min Freeway drive to warm it up.

My car had a tune up about 14 months ago, but is due for an oil change. Will this matter?

Thanks for any suggestions!


Warming it up well just before the test helps, as does a fresh tuneup including filters. Both help ensure as complete a combustion process as the engine is capable of.

Keeping the fluids and filters up and fresh also helps, as the more wear you prvent is the longer the engine will run cleanly.

You can go further by checking things like the operation of the EGR valve and repairing things as they begin to show signs of ineffective operation, but beyond that you’re preventative options are limited.

New Jersey state/emissions inspection is every two years. Three years ago my 93 Caprice just passed emissions (levels were 80-90% of the max allowed). The car was only driven 3 or 4 times a month.

Last year, I drove about 50-60 miles the day before inspection. This time the emission levels were 20-30% of the max allowed. I think the long drive made a difference. An oil change and a fresh air filter wouldn’t hurt your chances either.

Good luck,

Ed B.

Yes, change the oil and spark plugs, and especially the air filter if it hasn’t been changed in a while. Take the freeway drive to ensure it’s hot when you bring it in. If you’re looking for a magical gas additive, I’ve heard many claims, but haven’t see anything work 100% of the time.

Fresh spark plugs help so many car run smoother, and cleaner. If the spark plugs wires are old, changing those could help.
A correctly operating EGR valve keeps NOx values down.
While you wait in line for testing, don’t shut the engine off. You want the engine to remain at normal operating temperature.

Thanks for all of the great advice! I love this site!