jnaut

A friend of mine had an oxygen sensor on her 94 civic go out and she ran into troubles with the dealer. All the woman at the dealer told her was that her "heated" oxygen sensor went out. When my friend pressed the dealer further, the dealer claimed there was only one (1) sensor on the car, but there are two (to my knowledge). A pre-catalytic and post-catalytic sensor. My hunch is that the "heated" 02 sensor would be the PRE-catalytic sensor because based on my limited knowledge, the exhaust gases would be much hotter there, than after the converter.

Any advice would be helpful.

sol2hatch

unless you actually went under the car and saw two O2 sensors, then I think you are mistaken. On the older civics, there is one O2 sensor. The newer cars are like you stated, pre and post cat.

philosofy1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jnaut &raquo;</TD></TR><TR><TD CLASS="quote">A friend of mine had an oxygen sensor on her 94 civic go out and she ran into troubles with the dealer. All the woman at the dealer told her was that her "heated" oxygen sensor went out. When my friend pressed the dealer further, the dealer claimed there was only one (1) sensor on the car, but there are two (to my knowledge). A pre-catalytic and post-catalytic sensor. My hunch is that the "heated" 02 sensor would be the PRE-catalytic sensor because based on my limited knowledge, the exhaust gases would be much hotter there, than after the converter.

Any advice would be helpful.</TD></TR></TABLE>

since you friend has a 94 civic, it is a obd1 ecu set up. there is only one o2 sensor, which is located on the down pipe, before the cat. anything 96-up is obd2 ecu set up and yes those have a pre and post o2 sensor.

lucky for her now she knows the problem and is easy and quite cheap to repair.

B18C5-EH2

Exactly what model is this 1994 Civic?

CX, DX, LX, VX, EX, or Si?

If it's a VX then holy **** you're in for sticker shock, because they have an ungodly expensive 5-wire o2 sensor.

The other models?

Order a Denso or OE Honda sensor ONLY and call it a day.

Oh and lastly the 92-95 Civics are known for having the o2 sensor snap off inside of the manifold sometimes, so if this happens she'll also need another exhaust manifold too.

One of the many joys of working on 11-14 year old cars I guess.

jnaut

Wow, thanks guys for all the replies. FYI, she has an EX model, so I guess she won't be in for sticker shock. And however she gets it repaired, I'll definitely pass on the info about the sensor breaking off inside the manifold. That sound ugly with a capital 'U'.

Thanks to all who replied.

Sol2hatch, nope, no one has been under the car (except the dealer). There has been some confusion on this because the Autozone guy told her that there were two for the '94. But I think I'm trusting the advice from the people on this forum.

egsir2

on 94 civics there is a O2 sensor befoe the cat,but there isa heat sensor on the cat itself. maybe the woman at the desk got mixed up? if the heat sensor is gone there will be ared light on your cluster that you cant miss.

B18C5-EH2

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by egsir2 &raquo;</TD></TR><TR><TD CLASS="quote">on 94 civics there is a O2 sensor befoe the cat,but there isa heat sensor on the cat itself. maybe the woman at the desk got mixed up? if the heat sensor is gone there will be ared light on your cluster that you cant miss. </TD></TR></TABLE>

Absolutely WRONG.

There is nothing in a 1994 Civic's cat convertor in terms of any sensors at all. The "heater circuit" people refer to is in the actual o2 sensor itself, and again no matter what anyone else says there is only one o2 sensor on a 92-95 Civic.

Where do you guys come up with this ****? A fuucking red light on your cluster to indicate a bad heat sensor? Oh my God I don't think I can take this website any longer.

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jnaut &raquo;</TD></TR><TR><TD CLASS="quote">There has been some confusion on this because the Autozone guy told her that there were two for the '94. But I think I'm trusting the advice from the people on this forum. </TD></TR></TABLE>

Did they actually tell her there are 2 O2 sensors on the car or that they carried 2 different brands of O2 sensors for her car?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 &raquo;</TD></TR><TR><TD CLASS="quote">Where do you guys come up with this ****? A fuucking red light on your cluster to indicate a bad heat sensor? Oh my God I don't think I can take this website any longer.</TD></TR></TABLE>

LOL - I know what you mean....:shakes head:.