How to prepare for a smog check

A properly maintained vehicle should have no issues passing its Smog inspection but we do get asked quite often for advice on how people can make sure they are prepared before their Smog Check in Fresno. Here are some Smog tips that can help.

Make sure the check engine light is off. The check engine light being illuminated is the number one cause of Smog Check failures. The check engine light indicates a malfunction that could cause an increase in emissions that needs to be repaired.

Simply clearing the light and then having your Smog inspection done will not work. The vehicles computer needs to run a series of self tests to make sure that the emissions systems are working properly. Until these tests are completed the vehicle's emissions monitors will be incomplete and the vehicle will not pass the Smog Check. For more info about the emissions monitors check our page on them here:

If you have had repairs performed or the battery has been disconnected you can let your nearby Smog station know that and they should be able to check the vehicles computer to see if it is ready before starting the Smog Check.

Aftermarket parts

Aftermarket performance parts are another cause for failing a Smog Check. Your smog technician has no problem with you modifying your vehicle(many of us are car enthusiasts ourselves) but the parts do have to be approved. All performance parts are required to have a CARB approved E.O. number assigned to them in order to pass a California Smog Check. This number is either on the part itself or on a sticker that is to be applied under the hood of the vehicle for reference during the Smog Inspection.

Older vehicles(model year 1999 and older)

Vehicles 1999 and older still get what is called a tailpipe emissions test where the smog machine samples the actual exhaust coming out of the vehicle and measures the pollutants in the exhaust. With the tailpipe test it is much more important to ensure that the vehicle is properly warmed up and has been driven for a bit before the Smog inspection, usually 5-10 miles is plenty of warm up time. Another thing that can help is to make sure your vehicle has fresh fuel in it. A car that has been sitting for 6 months or more may have stale fuel that has started to degrade and can cause elevated emissions.

If your vehicle does happen to fail its Smog inspection our skilled team in Clovis CA will be happy to diagnose the emissions system and give you a breakdown of what needs to be done to ensure it passes the Smog Check..


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