Code 43, 41 91 EX

[rather_b_boatin]

My 91 Honda EX started bucking under load. After isolated incidents it did it bad on the highway and kicked on CEL. After CEL illuminated, it smoothed right out. (I assume bc this failed a sensor to safe value) I looked at these forums and some others and it seemed I had a bad O2 sensor, so I replaced it. Now the CEL illuminates after about 3 miles of driving but the car seems to run fine except that after $60 and a new O2 sens. I have to look at that ever-so annoying bright oarnge CEL. Also, don't know if this is realavant but the car smells like gas when I fill it all the way or take a right hand exit ramp at 50mph, I read somewhere that there may be a gas line leak under the back seat? Might this foul gas pres. and set a code? Thanks in advance for any help.

[somick]

Did you read codes after replacing O2 sensor.

What brand of sensor did you buy? Are you sure you conected it correctly?

Good luck,

Sam

[rather_b_boatin]

Bosch and it had a factory connector that fit perfectly.

[rather_b_boatin]

And it is still setting a 43 and once I pulled a 41 (heater sensor circut for O2 sens)

[somick]

Those codes are for O2 sensor.

I have heard that Hondas do not like aftermarket stuff. That might be the issue. As far as I remember Honda uses Denso for O2 sensors.

I know that nobody wants to pay twice, but I would try Denso for starters.

Good luck,

Sam

[rather_b_boatin]

I first tested the (new) Bosch O2 sens. according to my Haynes manual and it failed 2 out of the 3 tests. 1st test was sensor voltage during low/high rpms after engine warm, should have been <.5 idle to low rpms & > .5 during higher rpms. Never got above .016 volts. Next test it failed was heater circut never went closed loop to even get an ohms reading, let alone the specified ohms reading it needed to properly function. The only test it passed was no continuity between lead A and C/D. Voltage to the sensor passed as well. I suspect the heater circut is the one that was kicking the 43 and CEL since the ECU wants that heater circut closed loop after so long. Just my suspicion, I don't know those things all that well. Took the Bosch back to Advance Auto (with the recipt), explained my situation, they gave me credit for the Bosch and they had a Denso on the shelf, I walked out $5 ahead of the game and better running, no CEL Accord. Hope this can help someone out there. Somick, You were right on.