2000 Accord SE O2 sensor problem

I am trying to solve an oxygen sensor problem with my 2000 Honda Accord
with a 2.3 liter ULEV motor. A couple of months ago, the check engine
light came on, and along with it the idle got a little rough, and gas
mileage is down about 10 percent. I had the computer scanned at
Autozone, and they indicated that it needed a MAP sensor, which I
replaced to no effect. I had it rescanned, and it came up with codes
P1166 and P1167, which are the Primary O2 sensor and O2 sensor heating
circuit.

I ordered a generic Bosch O2 sensor and installed it as instructed. Even
after several weeks of driving (and I drive a lot) the light didn't go
out. I double checked my wiring, but everything looked okay, and even
redid the splices. With emmissions testing due in about 3 weeks, I took
the car to my neighborhood mechanic, who scanned it again. This time, I
am getting only a code P1167 (Primary O2 sensor heating circuit), and
was unable to clear the code, and the engine still idles a little rough.
I carefully checked out the sensor electrically, and I am getting
about 12 or 13 ohms across the heater, which seems reasonable. What is
more interesting is that I checked the voltage across the element while
it was running, and I seem to be getting about 9 volts across the
heater, but 14.2 volts from either side of the heater to ground.

I suspect it could be one of 3 things.

a.) The Bosch sensor is incompatible with the Honda ECU, in which case I
will have to shell out a couple hundred bucks for a new O2 sensor.

b.) A wiring problem, such as a high resistance connection between the
ECU and the O2 sensor. Should be able to track it down and correct it if
that is the case.

c.) A bad ECU

I don't want to have to buy a new o2 sensor if the problem is with B or
C, nor do I want to spend upwards of a grand on a new ECU, or probably a
couple of hundred on a junkyard unit if I am not absolutely sure. Any
ideas folks?

To respond off group, replace MyCaLlSiGn with my ham radio callsign

73 Bruce-N3LSY...-.-

 

Had you gone to your dealer in the first place you would not get the
runaround from all the people who think they know your Honda, but only guess
at what they're doing. They dealer knows your Honda, they have the
knowledge, they have the proper tools and they have the right parts. This is
just another example of where the dealer in the long run is cheaper and will
deliver a more reliable vehicle back to you. Unless you would like to
continue playing with the same problem week after week.
Oh, by the way, did any of your "experts" bother to clear the code for you?

Live and learn
Howard

 

there was a bulletin on this problem. not a recall, so if it's not a
warranty issue. call the dealer and ask about it. they were replacing
injectors and ECU's.
Chip

 

Usually, a 4-pin universal O2 Denso heater circuit should measure
about 4-Ohm. That could explain why the ECU is measuring an
inconsistent voltage drop or incorrect current amperage reading.
Japanese cars tend to do best with a universal Denso (OEM, $90)
And I tend to avoid Autozone parts and rely on import suppliers for
reliable parts.

Rick