I have a friend with an old 4runner. He just got it smogged in CA before sale. It failed because of "Gross Polluter" . I attached the VIR to show the exact numbers. The HC (PPM) and CO (%) were what failed by a lot. Any ideas what the problem could possibly be? Anything that ussually causes these numbers to be so high? PLEASE HELP!
Car failed smog...
- Thread starter druuu88
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Fourty-four
Guest
druuu88 said:
High HC (hydrocarbons) usually mean that the engine is not combusting all the fuel during each 4-stroke cycle. In other words, unburned gas always results in high hydrocarbons.
What year is the 4Runner? You might want to check the basics to make sure it isn't running too rich. Even something as simple as a bad oxygen sensor can cause the vehicle to run too rich, so don't rule that out either.
The good news is that the NOx is low, which does rule out the EGR system.
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Yeah after doing research online, i figured this out. Thanks a lot for the response. I plan to check spark plugs, air filter (just to be sure), and maybe even fuel injectors if the 02 sensor is good (it was just replaced 1.5 years ago). Also, I think the car has a slight oil leak which ive heard could be contributing to the smog failure (burning oil with gas=bad). Thanks again. anyone else have any opinions im all ears...
boston_kevin
New member
druuu88 said:
make sure the engine is thoroughly warmed up before you do the test.
I'd be checking the O2 sensors, plugs, and filters. Timing would be good to verify that everything is opening/closing when it should (depending on the age, this may not computer controlled). The catalytic converter should also be checked, as it may be contributing to the problem depending on how old it is.
