SPANISH-RICE;264365 wrote:
Google owns you

word... I think pretty much every Honda forum has a sticky of the engine codes...

Code 1 - O2 Sensor - Code 2 is for the one down on the cat. Which was not used in the US.
MAP, TDC & CYL (along others) helps determine the Pulse Width (PW) in which fuel is injected. With the MAP having the most control, out of all other sensors.

Testing requires a voltmeter.
The voltage on a properly working sensor should sweep between .1 to .9 volts 2-3 times a second @ 2500 rpm. Peeps with A/F Ratio meters, will see the reading moving/dancing around all the time. This means everything is working all right

Unheated O2 sensor have to heat up, and maintain 600+ degrees F in order to work properly. Until that temp is reached, the ECU sends out .45V, until it reaches operating temp. When temp is reached, the O2 sensor will send out .5V. Telling the ECU it's up to operating temp, and can now go into "Closed Loop" operation. That is, if all the "other" conditions are met too, like water temp, etc....

Voltages:

Lean - .1 volts
stoich - .5 volts
Rich - .9 volts
O2 sensors do not wear out... they fail due to contamination.

Silcon Depostits (from using gasket sealents that are not O2 safe)
Solvents, Lubricants, Cleaners, Adhesives
Gasoline Additives
Lead
Carbon Deposits (rich condition)
Engine Oil (burning or spilling)
Anti-Freeze (blown head gasket)
Clogged External Air Vents (dirt, ect...)
Running Lean (too much heat)
ECU damage can occure using the wrong sensor, due to the execessive current draw requirements of non-stock sensor.