What does the EGR light mean on a 1986 Mazda B2000 truck?

Answer

I don't know the specifics for a 1986 Mazda pickup, but EGR stands for "Exhaust Gas Recirculation".

Answer

The EGR light comes on at 60,000 miles and again at 80,000 miles. It is a way Mazda attempts to get you into a dealer. There are two wires one green and one brown, one of these two will be plugged into a white plastic connector on a single wire. (Under the dash at the far left) unplug the green or brown and plug in the other wire. Problem solved, start the engine and the light will go out.

Ron

AnswerThe EGR valve recirculates exhaust gas to reduce combustion temperature and NOx emissions which are formed under high heat. The EGR system does not lower HC emissions.

On the EGR valve is a pintle position sensor which provides data to the computer so it can detect proper operation. If the computer detects that the valve is not operating it will throw the EGR light, it is not simply a marketing scheme.