I have a 05 MCS R52 with 25000 miles and the service engine light on. I pulled a p0128 from a OBD and cleared it. It repeatedly come on and off and the gas cap is tight. I do not get great gas mileage (24) and the tailpipes look black to me. I live 250 miles from the closest dealer so I'm thinking about replacing the O2 sensor with a Bosch 13878 direct replacement from the internet. I've heard MINI will replace the O2 sensor but it is not practical because of location so I'll do it myself. Does this sound like a correct diagnosis (replacing the front O2) and where is it located?

 

P0128 is a coolant temp sensor fault, so I would start there. Be sure that the connector on the side of the cylinder head (between the head and bottom of the intake box) is properly connected. If it is, have it tested.

 

sorry my fingers don't work today, it's a p0138 not p0128

 

If memory serves, there is a recall for 05/06 O2 sensors.....

Should not cost a cent to replace. Call your MINI dealer.

To answer the last question. There are two on the MINI. One pre-cat sensor which monitors engine functions, and one post-cat sensor ( both identical ) which monitors the health of the cat....You can purchase a special socket to remove and install them. Not difficult to replace as a DIY.

 

Yup....10 years, 100,000 Miles.