Replacing oxygen sensors

[PacketPuppy]

Hi,

I'm trying to replace the two pre-cat oxygen sensors in my 1998 M3 as done during an Inspection service.

I can't figure out which sensors to order:

11-78-1-427-884-M209
Oxygen Sensor, on CATALYTIC, 990mm, 323i/is/iC (1998-99), 328i/is/iC (1996-99), M3 w/ 3.2L (1996-99), each. Some later E36 models use more than one sensor. Please check your car first before ordering.

11-78-1-437-943-M209
Oxygen Sensor, on MANIFOLD, 990mm, 328i/is/iC (1996-99), M3 w/ 3.2L (1996-99), each. Some later E36 models use more than one sensor. Please check your car first before ordering.

Can anyone advise?

Thanks!

[Keith M]

The second one since it is for the manifold, while the other states it is for the cat.

Keith

[PacketPuppy]

Thanks. This has to be the most confusing part to order. I called Pelican and they stated the first one, 884. I am very confused.