I have code P0036 and check engine light. I recently removed the valve covers in order to clean the cams which were a bit slushed up and causing issues to the HPFP cam follower. I verified all sensors were reconnected and have verified all hoses and vacuum liners are connected. I used Kreen to clean the cams and then installed new oil(3qts synthetic/1qt MMO). Idled for 10 min...dumped..and replaced with new motor craft synthetic and filter. Ran it to my inlaws for about 20 miles with no codes. On my way back the CEL came on after 2 miles. Code p0036 oxygen heater sensor bank 1 sensor 2.
Any ideas? Car is running great btw.
Thanks in advance.