Hi everyone,
I own a 1998 2.5 Boxster which is great fun to drive but my problem is the after cat o2 sensors. I can find them on the diagnostic machine but they are not to be found on or after the cat. I can not see any connections where the should be either.
Is it possible my car has only one per bank, in front of the cat?

 

you should have four. 2 ( left and right) at about the 12 o'clock position in the pipes just aft the flange where the cat pipe connects to the manifold and 2 at the exit of each cat. Item 323 below illustrates the two locations.

 

depends on where you live.

 

ok, my car was built in Europe, does that make a difference to number of o2 sensors?

 

thanks for the diagram, my cats have bungs instead of after cat sensors

 

most rest-of-world (ROW) cars don't have secondary 02 sensors.

 

They were all built in Europe. Where was yours originally titled/registered?

 

I pulled the parts catalog off of the Porsche Classis website for the European delivered cars and it is still showing 4 O2 sensors. I don't know what country delivery your car was constructed for, but you could always search the parts diagram for that market and see what it shows.

 

it's one of the tricks - set your ECU to ROW and then you can remove the second set of o2 sensors and run an exhaust without cats because row has different (lower) obd requirements and you won't get a cel.

different requirements:
- no test of cat aging, so no need for the second set of o2 sensors
- emissions testing based on running condition. north american (NA) is based on start-up condition which necessitates the additional cats to address the extra fuel.

ROW also lets you delete the secondary air injection (SAI) system.

 

How do you set your ECU to ROW?

 

it's a production. google (or search this forum) for 'porsche row flash' or similar.

 

Thanks, very helpful.