Most engines have an exhaust gas recirculation (EGR) valve to help pre­vent the formation of oxides of nitrogen (NOx). NOx in the presence of sunlight forms smog. Read More

Most vehicles manufactured since the mid-1980s are equipped with halo­gen bulbs. If the bulb burns out, it can usually be replaced without replacing the entire headlight unit, because the bulb and headlight are separate. This…

By following the procedure described in this article, you may be able to repair an automatic transmission that is slipping. "Slipping" is the term applied to a transmission that doesn't shift gears at the proper…

EVAP, an abbreviation for fuel evaporation control system, prevents gaso­line vapors from escaping into and polluting the atmosphere. When an EVAP system sustains damage, an engine can idle roughly and/or stall, and there will probably…

Fuel injectors are electrically operated solenoid valves that spray gasoline into cylinders of an engine that is equipped with a throttle body or multi-port fuel-injection system. If an injector doesn't receive elec­tricity because of a…

Most engines with carburetors have a heated-air inlet system integrated into the air-filter housing. This system is sometimes referred to as THER-MAC, an acronym for thermostatic air cleaner, or EFE, an acronym for early fuel…