Trouble Code 41 R

[vamustangman]

I ran a computer test on the engine and got trouble code 41R, "heated oxygen sensor circuit indicates system lean right side", what exactly does that mean? And more importantly how do I fix it. Its a 1991 explorer 4x4 with a proud 190,000 miles on it. Thanxs

 

[93TwotoneXLT]

Basically, your oxygen sensor has tanked, and you need to replace it. A 91 X only has one sensor, which is located just beyond the "Y" junction on the exhaust, right beside the tranny bellhousing. Go to ford, pep boys, etc, and buy yourself a new sensor, take the old one off and put the new one on. May want to spray some penetrating lube on there and let it sit for about an hour(maybe more). Also, of coarse, let the vehicle cool down before you start putting your hands around that exhaust! Hope this helps.

P.S. Also, after you have completed the repair, make sure that you reset the computer to get rid of the code. You can do this by a code reader(if you have one) or you can disconnect the negative battery cable(which I would do anyway as a precaution before you take the old sensor off) for about 20mins. When you start it back up, let the X idle for about 10mins, followed by about 30 mins of judicious driving, so that the computer can "relearn" all of the sensors, idle, etc.

 

[vamustangman]

Well that sounds simple, thanks for the help.

 

[SVO42]

Also, if that one has gone bad, chances are the other one will go soon, too. It would be best to replace both at the same time. O2 sensor performance degrades over time.

 

[MrShorty]

Just a note: '91's only have one O2 sensor. '93 was the first year for a dual O2 system on the 4.0.