Any tricks to passing an emissions test?

[Agentbolt]

Registering my car here in AZ for the first time. In NH I never had to worry about emissions testing, here in Tucson of course you have to get it done before. I drive a 1992 Mazda Protege. I've never seen the Check Engine light come on, but I've also never had anything in the fuel/exhaust system looked at before, so I'm basically going in blind.

Are there any tips/tricks that actually work that'll help it pass? I'm sure those bottles of stuff you can throw in the gas tank are snake oil, but maybe there's some other stuff that does work. Do smaller cars like mine generally pass more easily? Is the emissions test generally hard to pass in the first place, or is it pretty much a formality to keep cars belching clouds of smoke off the road?

Thanks!

 

[Gunslinger08]

http://www.heartland.org/Article.cfm?artId=13139

 

[Agentbolt]

Yeah, I'd seen that on Google. I was just wondering also about how stringent a test it is, like what the pass/fail ratio is or something, and if the type of car affects the chances of passing or not. I guess I'll just find out tommorow. Thanks though.

 

[Captante]

If its been a long time since your last tune-up, now would be a good time to get one done ... also roughly a week before you go for the test (or long enough to burn through a full tank of gas) use a strong fuel syetem cleaner to get most of the crap out of your fuel injection system.

Edit: Note that you need to make sure you get all of the fuel system cleaner out of your gas tank at least a day or two before going for the test because when its actually in the fuel system it will increase emissions & could cause you to fail.

 

[yhelothar]

Don't you get one free retest at most places if you fail?
I failed the first time when I bought my used 99 miata.
Got it fixed, and they retested it for free.

 

[funboy6942]

Do not use any thing added in to the gas, sometimes it will give it a worse reading then it normally would. If you want to pass here are some things you can do:

1st is do a tune up, if the car fails all the time then start doing these things to it:

Change the plugs out for ones that are 1-2 steps hotter running then normal.

Remove your air filter to allow no restriction of air getting into the intake, provided where you take for the inspection doesnt check for this.

Find the hose going from the valve cover to the throttle body and remove it, wad up some paper and shove in the hose. This will make sure it doesnt suck up any gases from the crank case and return it back into the intake to get re burned. Before taking car for the test make sure this will not make the check engine light come on. It may be a good thing to save this for last and make sure not to turn your car on and off a lot of times after doing it. Most systems will not kick on the light unless the system fails 3-4 times, so start the car, plug the hose, take it right over for the test.

Do not burn high octane fuel, and try to go with as little gas in your tank as possible. High octane fuel is harder to burn, so it will lessen the chances of spark knocking, lower octane will burn faster and more completly, your spark sensors should retard the timing if it senses any spark knocking if your car is equipped with any. Also with less fuel in the tank the car will start to burn leaner, especially if it is really low, gallon or less, not good on the cats to do this all the time, but just to go get the testing done, wont do a thing to your cats, just be sure there is a gas station close by to go get some gas right away.

Make sure to take it to the test station off the highway, or beat the hell out of the car all the way there, flooring it from stop lights, and so forth. This will not only heat the engine up good, but blow out any carbon build up you may have on the pistons, valves, exhaust system prior to taking for test.

Also while in line, if there is a long line, try hard to go when there is none or a few cars, but if there are some, clear the engine out several times as you wait.

I bought a 88 cougar, that failed big time when I took it in the first time. Brought it back the next day doing the above, along with taking carb cleaner to the intake, and it almost didnt even register that it was running. It had hardly anything coming out the tail pipe at all, the guy asked me what I did, told him a tune up

I been doing this to all the cars I buy that fail the test the first time around, never had one not fail after I was done with it so I know it works. Just be sure to remember to put the air cleaner back in and remove the wad of paper from the hose right away, and for gods sakes, dont do it where they can see you after you leave the place