Disconnecting the battery for a minute will reset the on board computer which in turn can cause a self calibration after the battery is reconnected and the engine is started. Whether that causes it to pass a smog test really depends if the computer actually needed to be reset. The probability is pretty low that reseting the computer alone will solve the problem; that is unless some other adjustment was made. For example when replacing a sensor or adjusting the ignition timing it can be good to reset the computer so it will recalibrate after the changes to the engine were made.
Here is a tip: the emissions will improve by retarding the timing. The allowed tolerance is +/- 3 degrees. Normally you set the timing to zero degrees with the computer disconnected. However, setting the timing to -3 degrees (retarded) is still within spec and can help it pass. You can get a timing light at Harbor Freight for $12.
Another tip: synthetic oil is supposed to be smokeless. It may help a little but dont expect a huge improvement.
Another tip: Premium gas is better when taking the test
General advice would be: fresh spark plugs, good spark plug wires, distributor cap and rotor. Make sure motor is fully warmed up first. Try to fix vacuum hose leaks if you can find them.
Probably not as the emissions test (Smog test) is carried out by inserting a sensor into the exhaust pipe.
No, the odometer is not part of an emissions test.
If it came with one from the factory, yes if you want to pass emissions test.
I never replace it ,only if you need to like before a smog test so it can pass emissions
No, it will not pass the smog test with a defective or removed O2 sensor.
Your 1977 Datsun 280Z may not pass a smog test due to several potential issues, such as a malfunctioning catalytic converter, faulty oxygen sensors, or excessive emissions from the engine. Additionally, if the vehicle's ignition system, fuel injectors, or exhaust system are not functioning properly, it could lead to higher emissions. Older vehicles often have wear and tear that can affect performance and emissions levels, making them more challenging to pass smog tests. Regular maintenance and addressing any engine codes can help improve the chances of passing.
A truck with an electric cutout may not pass smog tests, as these systems can alter emissions and potentially increase pollution levels. Smog checks typically require vehicles to meet specific emissions standards, and modifications like cutouts may not comply with regulations. It's essential to ensure that any modifications are legal and do not interfere with the vehicle's emissions control systems. To ensure compliance, it's best to consult local emissions regulations or a professional mechanic before the test.
the opdomiter does not work, will it pass smog? opdomiter, not sure what that is. Please define.
Yes!
use a scan tool even a basic one from autozone if you know the guy working there he can reset it on the scan tool, you can disconnect the battery for 2 days. when i had mine unplugged doing some motor work, I had to drive around to pass emissions pcm had reset so i could pass the emissions test. hope this helps.
The check engine light (service engine soon) comes on and stays on when a problem is detected by the self diagnosis system of your vehicle. Generally, the problem is in the emissions or something that is affecting the effectiveness of the emissions, but other causes can trigger the light to come on, too. To determine the cause, the vehicle will need to be taken to a parts store or a shop that has an OBD2 scanner, or for 1995 and earlier models, an OBD1 scanner, While a scanner will not give you the magic answer, it will give you a code that narrows down the problem area. If the cause isn't repaired and the light is simply reset, you will fail the smog test.
No