hon2984

96 civic cx stock d16y7 think... 1.6 L non vtec. any way CEL came on.... pulled codes ,front O2 sensor heater circuit, cylinder 1 misfire, cylinder 2 misfire, cylinder 4 misfire, random misfire. I'm pretty sure the misfire codes are from it dying on me but I checked the cap n rotor and replaced them. It seems to run a little bit sluggish, but not that bad seems to have more of a low idle than anything sometimes will die but usually holds low idle round 300. So I'm left with the O2 sensor code. I know what the heater circuit is sopposed to do, I check it and there is no resistance between the heater pins. all data says should be between 10K ohms and 40K ohms. I have a O2 sensor laying around from an EG brand new .... pins seem to line up the same.... but its heater circuit measures 8.5 K ohms.... I'm wondering If this would work? Save me 60$ It was in a Z6...

Former User

Check the coil and ICM inside the distributor.

hon2984

plan on pulling codes again tomorrow to see if the misfire codes are still there or not.

Former User

Are all four plugs fouled by the misfiring and running rich? If not, a bad heater element would not generally cause random misfires.

hon2984

I know those two should not be related... but through fuel injection some weird things happen.... like I said it really only seems to affect the idle... which is odd to me too. I was thinking maybe it could be affecting the O2 sensor signal to the ECU makeing the A/F ratio not correct... if the heater circuit went out then chances are the rest of it could be bad too.


Also It died on me the other night while still rolling and I just let the clutch out and basically ran started it... I was thinking that could have been where the misfire codes came from.

Also limp mode would retard ignition timing as well I would think which should affect idle a bit.


I was really more curious about if the EG sensor would work, the plugs are the same, the heater circuit pins are in the same place. but it has different colored wires so I wondering if that should work.

Former User

The misfire codes indicate that you have more than just an idle problem and therefore represent the issue where you should concentrate your effort. When the heater element code is thrown, it forces the ECU to ignore all O2 sensor inputs, causing the engine to run in open loop. Therefore, O2 sensor inputs are unlikely to contribute to the misfire codes. This is why I suggest that you test the coil and ICM.