Hey guys my lady friend has a 2006 nissan sentra and recently threw a code for the rear 02/cat on the car. i changed the rear o2 sensor and the light went away for about 40 miles. the car just started jerking and surging but stays running? any nissan guys know what i should check to see if the issue can be resolved its a 2006 1.8l. Thanks
accel? decel? idling? more info… 
plugged cat possibly?
it seems to happen under accel. and sometimes idle no decel. cat is not plugged either.
MAF
also check IAC
I’m gonna stalk your girl now that I know what she drives, awesome.
Thanks i will look into these