Civic-EG.com Forum 3.3.1

- Sat May 15, 2010 4:56 am #194371 My check engine light read a code saying a need a new O2A which is the oxygen sensor #1 where is this located, the one on the header?

[Ajax1989]

- Sat May 15, 2010 6:31 am #194389 if you have a obd1 motor you have only 1 o2 sensor and its not hard to find its on the header around the area where your engine stamp is

there are 2 parts to your o2 sensor
*the air sensor it self which reads the air(exhaust) and adjust your a/f ratio
*heater, your o2 sensor has a heater which heats up the air, to help the cat converter heat up faster

if your gettin one of the 2 codes just replace the o2 sensor

- Sat May 15, 2010 6:52 am #194396 In order to make my check engine light go on I needed to drive my car around first and then I parked it and left the car on and read it was the Oxygen sensor then I decided just to make sure I parked the car and unplugged the sensor right on the header and then I did another diagnostic reading on it and it read differently making it a Oxygen sensor heater. I did the wire way with reading the engine myself the first time driving it flashed once fast meaning #1 oxygen sensor then I unplugged and did the reading again and it flashed 4 long times then 1 fast meaning 41 and that is oxygen sensor heating, I'm confused.

[Ajax1989]

- Sat May 15, 2010 7:24 am #194404 ya if you unplug the o2 theres no way the heater on the o2 will work so it thorws a cel

- Sat May 15, 2010 7:45 am #194405 Ohhh okay! that helps a whole lot now I will go buy and O2 tomorrow then.

- Sat May 15, 2010 7:56 pm #194464 I just bought a new O2 sensor and the car still does the same thing. I even unhooked the battery unplugged the fuse and unplugged the ecu and plugged it all back in, but when my check engine light comes on and I try to diagnose it the check engine light just shuts off, but then I unplug it then it turns on again any idea?

[suspendedHatch]

- Sun May 16, 2010 3:00 am #194562

there are 2 parts to your o2 sensor
*the air sensor it self which reads the air(exhaust) and adjust your a/f ratio
*heater, your o2 sensor has a heater which heats up the air, to help the cat converter heat up faster

if your gettin one of the 2 codes just replace the o2 sensor

Dear god!

There is no such thing as an air sensor. Air is 80% nitrogen. Exhaust is not air.

The O2 sensor heater is in no way attached to the cat converter. It doesn't "heat up air". It heats up the O2 sensor itself. The purpose of the O2 sensor heater is to get the O2 sensor working almost immediately upon cold engine start, because they don't work until they're hot. Older sensor relied on exhaust heat, but then they found out that most of the pollution a car makes occurs when the engine is warming up. So they built an electric heater right into the sensor. That's the difference between one wire O2 sensors and four wire O2 sensors found in OBD1 cars.

- Sun May 16, 2010 3:08 am #194564 you seem to know a lot about engines so what do you think could be wrong? Why the car sputters into gear, it almost sounds like the engine is either too much or too little gas.

[suspendedHatch]

- Mon May 17, 2010 3:50 pm #194870 Something like that has to be diagnosed in person. People here can give you some good starting points, but you'll need to give a whole history of the engine and be a lot more descriptive about the problem.

Also, a lot of times me or someone will lay out some testing procedures but then the op isn't willing or able to go through the trouble. Everyone just wants to try replacing random parts until they get lucky. But it's cheaper to take it to a mechanic.

Do you have a multimeter? A Haynes manual? Have you downloaded the Helms?