Hello All

I just inherited a 2003 Honda Accord 2.4 liter Auto 37K It has a check engine light. I got the code run at autozone. These were the results: It is a code malfunction that exists in the heater circuit for 02 sensor 2 in bank one, 02 sensor one is closest to the cylinder head.

I would like to try to repair it myself. Honda is willing to rape$ me and that's about it for the repair. They won't even tell me which o2 sensor it is to replace:

My questions are how many o2 sensors are there? Which one is it? Would replacing the sensor include relpacing the heater circuit oris this part of the connector to the sesor. I have replaced sensors before so the mechanical end of it is doable. I just need to figure out which sensor to replace?

In addition I ahve a service engine soon light although the oil&filter/ air filter/tires rotated have been done. I thought this would be sufficient at 37K. Anything else recommended or this a light for the dealers to make $

Thanks
Mike

Any help for this would be great.

 

the o2 heater is included inside the o2 sensor, yes, so replacing the sensor should solve the problem IF it's not a wiring issue.

I'm assuming the 7th gen has 2 o2 sensors, 1 before the cat, 1 after it, just like all other OBD2 cars but I could be wrong, 7th gen is not my forte.

on my 6th gen the "maint required" light will come on after 6k miles if it's not reset. they probably just didn't reset the light after the service.

 

for 6th gen(or even for later honda also), you need to use OEM harness sensor or it will throw a code, people had problem with heater circuit code even with brand new bosch sensor.

it doesn't affect gas mileage apparently

 

Honda's nomenclature runs like this
Bank one / sensor one
Bank one / sensor two
Bank two / sensor one
Bank two / sensor two

Four (4) Cylinder Hondas utilize either Bank one / sensor one (or two)
Sensor one is the first in the exhaust track - mounted prior to the Catalytic Converter. It will be either a one or two wire sensor which does NOT have a heating element
Sensor two is the second in the exhaust track - mounted after the Catalytic converter. Since it's the furthest from combustion heat, it is built with an intigral heater and will sport either three or four wires.

The "service Engine Soon" lamp is lit in responce to the O2 sensor heater element failure (indicates a code is available)
The "maintaince required" flag is a mechanical reminder which counts in multiples of 7500 miles. It can be reset by the insertion of your ignition key into a slot "thingie" in close proximity to that flag.

P

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by P_Adams &raquo;</TD></TR><TR><TD CLASS="quote">
Sensor one is the first in the exhaust track - mounted prior to the Catalytic Converter. It will be either a one or two wire sensor which does NOT have a heating element</TD></TR></TABLE>
Is that specific to the 7th gen models only? Not true for 6th.

 

I believe that holds true for all OBD2 systems (considering the codes don't change fron year to year / car to car.
The Exhaust manifold detail (1998 EX 4cyl) shows a dual wire sensor attached to the exhaust mainfold (IE: primary (position 1)) non-heated O2 sensor ($98.00)

http://www.hondaautomotivepart...81%29

Position one (1) O2 sensors are considered "Upstream" (a/f ratio verifying)
Position two (2) O2 sensors are considered 'Downstream" (converter efficiency check)

http://www.oxygensensors.com/location.jpg

P

 

I was wondering about that. What do they mean by Sensor1/ Bank one, Sensor1/ Bank two. It's just one Sensor right?

 

4 cylinder
Bank one / sensor one - Exh Manifold - primary a/f monitoring (upstream)
Bank one / sensor two - After Converter - secondary converter efficiency verification (downstream)

V6 '96-2002
Bank One / sensor one - y-pipe prior to Converter - A/F monitoring (upstream)
Bank One / sensor two - After Converter - Converter efficiency verification (downstream)

V6 '03-
Bank one / sensor one - prior converter L/S Exh Manifold / Converter - A/F monitoring (upstream)
Bank one / Sensor two - after converter L/S Exh Manifold / Converter - Converter efficiency verification (downstream)
Bank two / sensor one - prior converter R/S Exh Manifold / Converter - A/F monitoring (upstream)
Bank two / sensor two - after converter R/S Exh Manifold / Converter - Converter efficiency verification (downstream)

http://www.hondaautomotivepart...V6%29

P

 

So there are 4 Sensors on the exhaust. 2 O2 Sensors, and 2 A/F Sensors.

 

Up thru 2002 both Inline 4 and V6 both had two O2 sensors
From 2003 the Inline 4 moves the Primary O2 sensor from the Exhaust Manifold to the Downpipe and the Secondary O2 sensor remains after the catalytic Converter.

http://www.hondaautomotivepart...L4%29

From 2003 on, the V6 had 4. Two on the l/s Converter assembly and two on the r/s Converter Assembly.

P

 

since the car has only 37K on it you should be able to get that fixed under emmissions warranty

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by P_Adams &raquo;</TD></TR><TR><TD CLASS="quote">I believe that holds true for all OBD2 systems (considering the codes don't change fron year to year / car to car.
The Exhaust manifold detail (1998 EX 4cyl) shows a dual wire sensor attached to the exhaust mainfold (IE: primary (position 1)) non-heated O2 sensor ($98.00)
</TD></TR></TABLE>
my 98 EX 4 cylinder has a 4-wire heated o2 sensor. all the motors I've installed in it have all come with heated o2 sensors.