Code 41 (CM) Code 42 (KOER)

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Dec 14, 2004 | 10:25 PM

genueix

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Code 41 (CM) Code 42 (KOER)

Just making sure that these codes both indicate a failed HEGO sensor. 41 is system too lean and 42 is system too rich. If anyone has had these codes before, let me know before I rush out to pay for a sensor that might be good in the first place. My Check Engine light came on just as I was pulling into my driveway.

Nov 4, 2005 | 07:43 PM

ctch88

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I found this thread unanswered when searching tonight and was wondering what the fix was for you. I just pulled codes and got 41 and 42 at the same time, meaning that "HEGO switching detected always LEAN (right side)" and "no HEGO switching detected always RICH (right side)" respectively. Umm... this seems a little contradictory, do I need to replace the HEGO?

thanks,
kyle

Nov 5, 2005 | 09:30 AM

greystreak92

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Joined: Sep 2002

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From: Gateway to the West

Yes. Left and Right mean nothing in the Bronco since there is only one O2 sensor on them until late 95-96. However, getting BOTH codes means the ECM can't obtain ANY information from the O2 sensor. So, its either failed or the connections to it have.