oxygen sensor

[snooper0069]

will the oxygen sensor cause the check engine light to come on and off as you drive .i recently had the ford dealership to put my 1993 4.0 explorer on the diagnostic machine and they said it didnt show any codes . they also told me that this 4.0 model runs rough from the factory. it does run rough when it idles but down the road she does great. i just checked my fuel milage and it shows 22.6 mpg. another prob i have is sometimes the exhaust will smell like propane , but not all the time .

any suggestions would be appreciated

 

[88vert]

Yes a bad 02 sensor will make your check engine light go off and on,might want to check your fuel pressure regulator too for the smell

 

[kardinal]

Originally posted by snooper0069
will the oxygen sensor cause the check engine light to come on and off as you drive .i recently had the ford dealership to put my 1993 4.0 explorer on the diagnostic machine and they said it didnt show any codes . they also told me that this 4.0 model runs rough from the factory. it does run rough when it idles but down the road she does great. i just checked my fuel milage and it shows 22.6 mpg. another prob i have is sometimes the exhaust will smell like propane , but not all the time .

any suggestions would be appreciated

most definately (ford is notorious for having bad o2 sensors), my 97 has a permanent CEL from 2 of the 4 o2 sensors being bad. also, the 'propane' type smell means its running way too lean, which is most likely what burned up the o2 sensors.