355 O2 sensors

I'm replacing my cats and think I will put in new 02 sensors to be safe. Can someone tell me the Bosch Part numbers. I found a 13819 & 13820 doing some research. I'm wondering which is the pre-cat and which is downstream? Are these good P/N's?
Thanks in advance.
1999 F355 Motronic 5.2

 

Here you go m8
def the right part numbers as i fitted 2 new ones on my 355 (5.2)
I only changed the front ones though bought them via ebay (gen bosch)
just under £70 each inc postage although i see your not in the UK
Front O2 sensors : 0 258 003 819
rear O2 sensor : 0 258 003 820

 

Oh genuine Bosch plug straight in so the new ones i fitted are exactly the same as the ones i took out.
If you go NGK route then you have to cut the plugs off and splice the wires.

 

Chris, would these part numbers be the same for the 2.7 cars?
Thanks in advance.

 

Just did mine a week or so ago.....

Pre Cat: Bosch 13819
Post Cat: Bosch 13820

 

Good to know! I've always assumed that there would be splicing involved if I changed mine.

 

I was 98% sure that was the deal. Thanks for confirming it.