I just jumped the ECU and it threw code 41 witch is Primary Oxygen Sensor - Heater circuit malfunction. Does this mean my sensor is fouled? Only reason i ask is because it says heater circuit whatever the **** that is.

If it helps...i just replaced this and the CEL is still on, throwing the same code. Is something making me repeatedly foul sensors, or do i just have to reset something?

I did run a search on here, got alot of CEL threads, but none specific to 41 so i figured i'd start another.

Also, Primary is considered the one on the uppermost part of the header correct? Because that is the one i replaced.

Thanks.

 

the primary O2 is the one that is before the cat.

A heater code is usually indicated if the O2 has gone bad. It can also mean a wiring problem.

a four wire O2 sensor has two parts, the actual oxygen sensor and a heater element. Its used so the O2 will acheive operational temp faster than relying on the exhaust gasses to heat it up.

 

Thanks Relic. I understand now.

On the stock exhaust manifold of my 99dx, i actually have 2 sensors before the cat. So im still not certain as to what one is primary.

Since it was an OEM plug o2 i can rule out a wiring problem, and as i said before...could the light just be on for the hell of it, after i replaced the sensor? I didnt drive around yet, just idled it for a bit and the code stayed on.

If this was the case...and i replaced the sensor, and started it back up..would the CEL immediately go off?

Thanks again.

 

did you reset the ECU after you replaced the O2?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by I Shot 50 Cent &raquo;</TD></TR><TR><TD CLASS="quote">Thanks Relic. I understand now.

On the stock exhaust manifold of my 99dx, i actually have 2 sensors before the cat. So im still not certain as to what one is primary.

Since it was an OEM plug o2 i can rule out a wiring problem, and as i said before...could the light just be on for the hell of it, after i replaced the sensor? I didnt drive around yet, just idled it for a bit and the code stayed on.

If this was the case...and i replaced the sensor, and started it back up..would the CEL immediately go off?

Thanks again.</TD></TR></TABLE>

No you goin to have to reset your ecu.

 

my cell only comes up while driving sometimes.. does this mean the sensor is going bad?

 

Goooood ****, reset the ECU and everything is gravy. Thanks for the help and i apologize for startin a thread before i tried more ****

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JCracer723 &raquo;</TD></TR><TR><TD CLASS="quote">my cell only comes up while driving sometimes.. does this mean the sensor is going bad? </TD></TR></TABLE>
it could mean that the heater is starting to show signs of age, it could also mean that there is a connection going bad somewhere.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by I Shot 50 Cent &raquo;</TD></TR><TR><TD CLASS="quote">On the stock exhaust manifold of my 99dx, i actually have 2 sensors before the cat. So im still not certain as to what one is primary. </TD></TR></TABLE>

A stock 6th gen Cx/Dx exhaust manifold does NOT have 2 O2 sensors before the catalytic converter.