DC5r - Engine Light on but nothing wrong with engine ?

[aaronng]

Alrighty..

Ill have it checked when I get home and come back if I have stuffed up or anything =P

Thanks again !

Try not to stuff it up. Having the clip in the wrong holes can cause a short and damage your ECU! Get it correct the first time.

[WuackR]

Ok, came back with the results LONG LONG LONG LONG SHORT (PAUSE) - then same pattern again...

I've checked both links you guys posted on the previous page and found its either..

41 - Primary oxygen sensor heater
41 - Air Fuel Ratio (A/F) Sensor (Sensor 1) No Activity Detected / Air Fuel Ratio (A/F) Sensor (Sensor 1) Signal Stuck Lean
41 - Air Fuel Ratio (A/F) Sensor (Sensor 1) Heater Circuit Malfunction
41 - Air Fuel Ratio (A/F) Sensor (Sensor 1) Heater System Malfunction

Umm, are they pretty much the same ? Me thinks I have no heater for winter =(

[WuackR]

Oops, forgot to add..

To have this fixed (and to make CEL stop flashing), is there a DIY for this ?? or must I bring it back to the mech's and have them fix it ?

[GEG]

41 is the common code for DC5's and EP3's after transmission work, Indy from IS Motor Racing told me that Honda advised him it is an issue with the chassis design. The vibrations of removing the header go through the gearbox and break the sensor, or something to that effect.

What it means is the sensor is broken. It's not cheap, about 300-350$, but i have driven around before with a primary sensor out, and didn't notice a difference. There is still a sensor after the catalytic converter, which is monitoring the air to fuel ratio, so you shouldn't be running rich or lean. Fuel consumption shouldn't change too much if anything. If it doesn't bother you, i say leave it.

Otherwise, pickup a new sensor from Honda, and get someone to help you plug it in under the car.

[WuackR]

Ahhh I gets, i gets..

So it pretty doesn't affect the car's ability to move whatsoever ? Just a broken sensor pretty much aye ?
In the long run, will it only get worse ?

[GEG]

Well it's already broken, so it can't really get worse!

In terms of driveability, it wont affect anything, so don't be scared to take it out on the road. All the sensor does is monitor the air fuel ratio and adjust the computer, but there is another sensor assisting (secondary sensor) so it's not like all hope is lost.

I'm sure it is there for a reason, so maybe you'll lose some economy, but i wouldn't say it's an urgent fix really, if you can live with it.

[WuackR]

I see..

I'll probably bring it up to get it fixed when I get it serviced soon.. but yes, thanks for the help also !
So to clarify things, it's the 'Air Fuel Sensor' that's broken aye ?

[GEG]

Yep, PRIMARY air fuel sensor

[WuackR]

Sweeett !

Thanks mang !

[chargeR]

Well it's already broken, so it can't really get worse!

In terms of driveability, it wont affect anything, so don't be scared to take it out on the road. All the sensor does is monitor the air fuel ratio and adjust the computer, but there is another sensor assisting (secondary sensor) so it's not like all hope is lost.

I'm sure it is there for a reason, so maybe you'll lose some economy, but i wouldn't say it's an urgent fix really, if you can live with it.

Good replies champ. One thing though, the secondary O2 sensor on a DC5 is only to check catalytic converter functionality and doesn't provide any sort of lean/rich feedback to the ECU. So it won't help with the primary busted. The ECU will default to open loop operation which will result in pretty rich A/F ratios as you mention in cruise and light throttle, bad for fuel economy but probably won't hurt the car.

[GEG]

^^ thank you for that, i can now fill in the blanks in the bits and pieces i knew!

[aaronng]

Check if the primary O2 sensor wire is broken at the sensor itself. Also check if they have clipped it back in, If you follow the wire, you will see a clip that is mounted on the a bracket just off the transmission. Sometimes they forget to clip that back on.

One problem with the clip method to read the CEL, now you know where the fault is, but you don't know if the sensor is busted, whether the wire snapped or if it has been left unplugged. The OBDII reader would tell you which of the four code 41 issues you have.

The problem is probably one of the three below:
41 - Air Fuel Ratio (A/F) Sensor (Sensor 1) No Activity Detected / Air Fuel Ratio (A/F) Sensor (Sensor 1) Signal Stuck Lean
41 - Air Fuel Ratio (A/F) Sensor (Sensor 1) Heater Circuit Malfunction
41 - Air Fuel Ratio (A/F) Sensor (Sensor 1) Heater System Malfunction

The first means it is unplugged or the power supply wire or signal return wire has snapped. The 2nd means either it is unplugged or the wire that sends power to heat the sensor has snapped. The 3rd probably means the actual wire is not getting any power, placing the problem further upstream.