Fuel Cap
The fuel cap is self-explanatory. If the gas cap is bad, we will tell you and sell you a new one so you can pass your Smog Test. Some stations fail you and then charge you for the gas cap, as well as another Smog Test Inspection.
Check Engine Light/Malfunction Indicator Lamp
Check Engine Light or service engine soon light on your dash that usually says "Check Engine, PCM, Engine" or has a picture of a motor. There are many different kinds. If this light does not come on, it fails the functional portion or the Smog Inspection. If it comes on but stays on, then it fails the Smog Inspection also. This light is an indication that there is a problem with your emissions system.
This does NOT mean the computer is bad. In 20 years, Autotek has replaced less than 10 computers (ECM) in vehicles. They normally do NOT go bad. Usual cause is a sensor out of range, or a disconnected wire or ground from previous repairs. Our recommendation to fix this problem, is find a licensed Smog Check repair facility. Approximately 98% of our second attempt failures are from people taking their cars to "Shade Tree Mechanics". We consistently see people spend more money getting their car fixed at home, than at a shop. Most repairs are under $600 at a licensed Smog Check Station.
Liquid Fuel Leaks
If your vehicle has failed this portion of the Smog Test it is indicative of actual fuel leaking from anywhere on the vehicle. Possible fuel leak locations are the fuel tank, fuel lines and and either the carberater or the fuel injection system.
PCV System
PCV is an acronym that stands for Positive Crankcase Ventilation. The PCV system recirculates crankcase vapors that are created inside of an internal combustion engine as a result of blow-by in the cylinders.
This portion of the test is a visual inspection of the entire system of parts to visually determine if there is any missing, modified or disconnected components.
TAC System
TAC is an acronym that stands for Thermostatic Air System. TAC systems have been historically used on vehicles with carburetors and attached to the air cleaner assemblies. The purpose of the system is to increase the temperature of the intake air charge going into the engine as this increases fuel atomizing and offers better cold start performance and emissions.
This portion of the test is a visual inspection of the entire system of parts to visually determine if there is any missing, modified or disconnected components.
EGR System
EGR is an acronym for Exhaust Gas Re-circulation that is utilized as a system of parts to introduce measured amounts of exhaust gasses (burnt fuel vapors) back into the intake manifold of a engine. The objective of EGR system is to utilize the inert exhaust gasses and introduce the gas into the intake air charge in order to lower combustion temperatures below 2500 degrees.
The importance of lowering the combustion temperature is to reduce and eliminate NOx gas that are created in the combustion chamber at temperatures above 2500 degrees.
This portion of the test is a visual inspection of the entire system of parts to visually determine if there is any missing, modified or disconnected components.
EVAP System
If your vehicle has failed this portion of the Smog Test it is indicative of actual fuel leaking from anywhere on the vehicle. Possible fuel leak locations are the fuel tank, fuel lines and and either the carburetor or the fuel injection system.
