2010 f150 with a 4.6 3v. CEL has been on constantly, throwing an o2 code p0150. ive had 3 of the same o2 sensors replaced and everytime this light comes back on after an hour or 2 of driving and stays on. so i basically just gave up on it cause the truck has been running fine. btw this was a local shop diagnosing and replacing the sensor. been on for about 2 years now. ANYWAYS ive noticed after oil changes the CEL goes off! ive changed oil 3 times since this light started coming on and only after an oil change does the light go off, but eventually comes back on after an hour or so of driving or after sitting overnight. so light bulb finally went off in my head could this be a pcv or egr issue?? im thinking crankcase pressure issue caused by pcv or egr, hence unscrewing the oil cap may release said pressure and light goes off. i dont know, newbie here. thoughts?

 

Sounds to me more like an intermittent electrical circuit fault.