LM3914 National Semiconductor.
10 LEDs 3 colors from lean to rich
1 - 1k Ohm resistor.
1 - 220 Ohm resistor.
A prototyping board.
There are three inputs. 02 goes to the oxygen sensor wire, V is the + 12 volt source , and the ground wire. Also check out National semiconductors' web site
the pins 1 and 18 are to the left of the letters LM exactly the was you see
them at the dia gram
leds have polarity they won't light up if you put them in the wrong way. Check polarity (one leg long one short using 4.5 to 6 volt battery)
resistors have no polarity but it is critical that you put the right resistor in the right place do not interchange.