1996 - 850 Turbo Sedan - Check Engine Light Question - Larry

[Larry]

My check engine light has come on two times in the past couple of weeks.
Both times the code was "front oxygen sensor". After the first time, the
dealer reset the codes; I drove the car for a few days .... maybe 50 miles
and the check engine light came back on. Had code read and reset at
Autozone today. So far light has not come back on.

Question: Is it likely the front O2 sensor is failing, or could there be
some other cause? Car runs fine with no apparent problems when check engine
light came on both times.

Thanks, .... Larry

 

[Mike F]

My check engine light has come on two times in the past couple of weeks.
Both times the code was "front oxygen sensor". After the first time, the
dealer reset the codes; I drove the car for a few days .... maybe 50 miles
and the check engine light came back on. Had code read and reset at
Autozone today. So far light has not come back on.

Question: Is it likely the front O2 sensor is failing, or could there be
some other cause? Car runs fine with no apparent problems when check engine
light came on both times.

Thanks, .... Larry

Vacuum leaks can cause front sensor codes, as can leaks in the exhaust
before the sensor (cracked exhaust manifold). However, the usual cause
is the sensor itself. Look for vacuum leaks, especially at the rubber
elbow on the end of the intake manifold by the power steering pump, and
under the throttle pulley cover.