Volvo Repair: 96 850 code p0141 02 heater curcuit, o2 sensor, heater element

Question
just bought a 96 850 with a ck engine light on and a p0141 code o2 seems to be switching any typical problems i would appriciate any info thank you  

Answer
What this means is that the heater built into the O2 sensor is malfunctioning (either a short past the heater element, its open, or its too slow to respond).  Its required so that the sensor will heat up faster cause it won't work until it's hot.  No matter what the cause is though you'll have to replace the oxygen sensor.  It should be a pretty easy job to do in your drive way, just beware that exhaust dissassembly can start easy and get real complicated when bolts get stuck or break off.  Have an extra car to drive to the parts store while you're workin on it cause you'll need it.  Hope that helps.

James