poss o2 sensor
hi guys i'm new on here (usually to be found on bmwland !)
i'm looking to broaden my search for info on o2 sensors.
my mates car (2000 e46 328 uk) is showing it's 'check engine' light, the engine symbol not the eml one.
i've got access to a fault reader but it's not bmw specific so is not very detailed in its descriptions.
codes are CB and E4 which i think relate to the o2 sensor for cyl 4-6 as it also mentioned 'bank 2'.
as it's not my car i don't get to fiddle with it all the time but the last time i did i checked all the plugs etc and cleared the faults. the light stayed off for about 25 miles.
i don't think i'm looking for an intake air leak or maf fault as it's only showing the fault on the rear cyl's, and it runs really smooth, no lumpy idle or hesitating.
next time i get the car i'm going to read the codes again to make sure it still shows the same fault, them swap the two manifold sensors over and see if the fault moves with the sensor.
any opinion will be apreciated especially if someone has had a similar problem, most threads i have read have had faults showing on both sensors that relate to intake problems causing waek mixtures.