Cats and o2 sensors

[dil]

i was wondering if i can change my cats to highflow ones in the stock exhaust will it change the bakpressure or jus make it run better

and how many o2 sensor does the 328is 97 have

[richie_s999]

I beleive its 4 o2, one per header, one after each cat....pic from realoem shows the bungs.....

http://www.realoem.com/bmw/showparts...53&hg=18&fg=10

[doogee]

You can run a highflow cat no problem.

And yes, there are 4 O2 Sensors on your car.

[dil]

can anybody recommend a place i can get all these items for a good price

[dil]

bump any help where i can get them all for a good price