phone number
(510) 733-5577
location address
636 A Street
Hayward, CA-94541
store hours
Mon-Fri 8:00 am to 6:00 pm
Sat 8:30 am - 12:30 pm

Frequently Asked Questions

Depending on manufacture year [MY], different strategies can be applied. Smog Check is the standardized test to make sure the emission system in your vehicle is working properly. For year 2000 or newer, you need to verify the On Board Diagnostic [OBD] system is functioning properly and without any recorded codes. For MY 1996 – 1999, not only OBD must function properly, vehicle must also passes the dyno-test. Also fuel cap is tested for leak. For MY 1995 and older, in additional to OBD [if equipped], dyno-test and fuel cap test, the evaporative system will be tested for leak. Above information apply to most vehicles with the manufacture year described. For commercial trucks, test can be varied depending on the weight of the vehicle. There are exceptions that will not be discussed here. Consult for more information. If you doubt that your vehicle may not pass smog check, you can opt for a pre-test.

To locate a Smog Check Test/Repair station for a complete diagnosis on smog check failure. List of Test/Repair stations are list in Bureau of Automotive Repair [BAR] website or visit to find out details. The strategies are to diagnose the smog check failure, to obtain a written itemized estimate, to repair the emission defect, to perform a pretest to verify the repair, and to retest vehicle. All diagnosis and repairs of smog check failure should be performed by a BAR certified Smog Check Test/Repair station.

Best source of information is found in owner's manual of your vehicle. Owner manual also list other vital fluid requirement and capacity recommended by the manufacturer such as transmission fluid, coolant, brake fluid etc. In general, regular [non synthetic] motor oil and oil filter should be changed around 3000 to 5000 miles, depending on the operating condition and other factors that degrade motor oil. Synthetic oil typically last longer than non-synthetic. Consult owner's manual for correct information.

In essence, the difference is the size of the oil molecules. Full or 100% synthetic oil has mostly uniform oil molecules. Regular oil has non-uniform oil molecules. Blend synthetic is the combination of regular and full synthetic. Uniform oil molecules help engine internal parts to move smoother than non-uniform ones. Note that the ratio of blend synthetic oil can vary from 1% full synthetic/99% regular to 99% full synthetic/1% regular. It's to the discretion of the vehicle owners to find out what they are buying in blend synthetic motor oil.

All newer vehicles are equipped with a TMPS (Tire Pressure Monitoring System) light or icon that will stay on whenever tire pressure falls out of normal range. The failure can be too low pressure or too high pressure. All tire pressure must be adjusted within the manufacturer specification which can be found around driver door jamb. TIPS: Check pressure when vehicle is parked preferably overnight. Don't forget to check pressure in spare tire. Use good quality tire pressure gauge. Some manufacturers require vehicle to be driven for a short distance before TPMS Iight will go off. Consult your owner manual for proper procedure to reset TPMS system.

This is one of the most commonly occurring problem in 1996 and newer vehicles. Loose fuel filler cap is the first place to check if fault occurs a few miles after fill-up. Other than loose fuel cap scenario, it is wise to have the problem diagnosed by a professional repair facility. However, a common misconception about Check Engine light diagnosis is that technicians can use code-reading tools to determine the exact problem that triggered the check engine light. In reality, the code tells technicians which engine or component parameters are out of range and which areas the defect may be found. The code does not detail the cause of the problems. That’s where the good old human brain comes in handy, as the technician uses experience, knowledge and expertise to diagnose the underlying problem. Diagnosis followed by repair in many cases in not a “one plus one equals to two” process. Therefore, it is prudent to have the repair facility which diagnoses the problem to do the repair. In that way, the diagnosis/repair/verification circle can be completed by the same technician.

Not all parts are the same quality. Part quality plays an important role in a lasting repair job. With all the convenience in parts purchase via internet, average vehicle owners have many choices in part purchase. Moreover, quality and price can vary in staggering range. However, most vehicle owners have no way of judging the quality of the parts by looking at it. OEM (Original Equipment Manufacturer) is always the first choice if price is a lesser factor. Certain parts are OEM only. For non-OEM aftermarket parts, always choose a well known national brand if available. Stay away from those unbelievably low price parts. Not only those inferior parts will compromise the reliability of your vehicle, but also may introduce other problems that do not exist before. In every sense of the words, you get what you pay for.

If your vehicle needs a smog check, you may expect a nerve-wracking experience. What if your car doesn’t pass. It could mean costly repairs and other unexpected expenses. Follows are steps that you can take to maximize your chances of passing smog check:

  • Check Engine light
    If your Check Engine light is on, not only it is an automatic smog test failure but also is an indication of emission components failure. There is a wide range of issues that can cause Check Engine light to stay on. It can be as trivial as loose fuel cap. Or as severe as mechanical defect in power train. So have the Check Engine issue properly diagnosed before smog check. If the Check Engine light is turned off without addressing the issue, it will come back on after a few miles. So if your mechanic tells you something needs to be repaired, get it repaired. Moreover, your vehicle will work in optimal efficiency when emission system is functioning correctly.
  • OBD II monitors
    If your vehicle recently needed a jump-start or battery replacement, you should drive your vehicle for at least 100 miles before taking the smog test. When the battery was disconnect, it erases the internal self-test monitors, including the emission monitors which are required to pass a smog check. Depending on manufactures, the emission monitor will usually be restored after 100 miles driving.
  • Oil Change
    Motor oil keeps engine internal parts moving smoothly. It also holds pollutants such as hydrocarbon (unburnt fuel) and microscopic worn particles. Dirty oil which is high in hydrocarbon will trigger a smog test failure. So oil change is a prudent and inexpensive way to increase the chance to pass smog check. While servicing your vehicle, ask the technician to do a visual inspection of the engine to catch any cracked, broken, or disconnected hoses that could contribute to a smog test failure.
  • Cooling system check
    Part of the smog test is running the engine at high speed while it’s stationary, which results in less air flowing through the radiator to cool it. Before your smog check, make sure your coolant tank is filled, along with the gas tank—a low gas level could expose the fuel pump and let vapor into the fuel line, which could cause your car to fail.
  • Drive in highway before smog check.
    The critical component in the emission system is the catalytic converter. It is responsible to convert harmful pollutants into less harmful emissions. But it needs to get hot enough to do its job, so be sure to drive at freeway speeds (on the freeway, of course) frequently in the two weeks leading up to the smog test in order to burn out any oil and gas residues.
  • If in doubt, do a pre-inspection The only certain way to know whether your car will pass or fail a smog test is getting a pre-inspection. Upon your request, a smog check facilities can do pre-inspections that involve all the same tests as the official smog check, without the results being recorded with the DMV. And if you get the pre-inspection done long before your registration is up, you’ll have plenty of time to fix any necessary repairs before the actual smog check.