How to Pass a Smog Test -- Tips

Learning how to pass a smog test is one of those essential bits of knowledge that every car owner in California should know. But there are a lot of pitfalls involved in passing a smog test. Some people inadvertently shoot themselves in the foot doing things that they'll think should help them pass a smog test but in fact cause them to fail. The biggest thing that people do wrong is buying more expensive fuel. People often have a conception that how to pass a smog test is to use premium 91 octane fuel. It seems to make sense right? More expensive fuel is probably more pure, which means it probably burns cleaner and gives off less emissions right? Wrong. 91 Octane fuel contains higher combustive chemicals, which means it's formulated to burn longer, in higher performance engines. If you put it in an engine that's not meant for high performance, the fuel won't completely burn up inside the chamber, meaning that every time a piston fires, a little unburnt fuel will be pushed out of the exhaust, causing much MORE emissions to come out of the engine. Buying premium gasoline for your smog test can cause an ordinarily healthy engine to fail miserably. Don't do it. But you can use this fuel additive listed below. It's cheap, and they claim to guarantee that you'll pass your emissions test!

Now I'm just as environmentally friendly as anyone. Just check out my other hubs on green technology if you don't believe me. Some people argue that altering your normal engine habits in order to pass smog is cheating and non-ecofriendly. To some extent I agree with them. But most vehicles that fail smog fail by only a slight amount. Not only that, but older, classic vehicles made before 1971 aren't required to be smog certified at all, which doesn't seem to make sense. I'm under the opinion that it's better to save money and eventually buy a fuel efficient, low emissions car, than to spend all your money fixing up the old car with outdated tech. I would much rather save money and ultimately buy a ecofriendly vehicle, than have to keep spending my money fixing the old clunker. But that's just me. The good thing about these tips on how to pass a smog test is that they won't work for the truly polluting vehicle. Like the picture to the right, some vehicles will simply fail smog anytime. That's why these tips are so great, because they only help cars that are already clean, not the truly dismal vehicle. So lets get to them! Tips on how to pass a smog test:

1) Use low Octane Fuel -- The lower the octane the better

We already discussed above that buying premium fuel can cause you to utterly fail your smog test. Go the other way. If you can find 85 octane fuel, use it. Don't use it permanently, just use it to pass the smog test. What happens is that lower octane fuels burn up faster while still in the combustion chamber, giving your engine the maximum amount of time to incinerate those pesky emissions, before sending them on their way.

2) Isopropyl Alcohol

I was recently informed that using rubbing alcohol to pass a smog test might be illegal. Using additives like methanol and ethanol to pass a smog test is illegal, but I wasn't able to find anything definitive about isopropyl alcohol. Using rubbing alcohol is risky though in general. It can damage the rubber seals that are very difficult to replace, once damaged. Damaged rubber seals within the motor can cause oil leaks into the combustion chamber and other unpleasantness. To be safe, and to make sure you're not breaking the law, I'd say pass on the rubbing alcohol.

3) Use a Fuel Injection Cleaner a Few Weeks Beforehand

It's always a good idea for your engine and fuel system to be as clean as possible before you go into a smog station. A few weeks before your trip, pour a bottle of fuel injection cleaner into your gas tank when you go for a fill up at the gas station. This will hopefully take care of some of the gunk and grime clinging to your fuel system. For more information, check out my hub on fuel injection cleaner.

4) Use a Fuel Treatment System

If you're really worried about passing your smog test, buy a fuel treatment system that specializes in lowering emissions. Lucas Fuel Treatment is one such specialized formula that seems to get some great results. I've read a lot of testimonials online and people seem to really like it.

5) Clean Your MAF Sensor

The MAF sensor stands for mass air flow sensor and helps to determine the amount of air to add into the fuel/air mixture. If your MAF sensor is dirty, it can cause the fuel mixture to be too rich in gasoline, which can lead to excess emissions. If you're interested, check out my article on MAF Sensor Problems for how to clean your MAF sensor in a quick and cheap way.