Headers and o2 sensors

[snapfrank]

i have headers for my 2001 boxster but there are no holes for the o2 sensors so what do i do with the sensors and will the car run if there not pluged in. there are 2 o2 sensors on each side 1 and 2 which can i cancell.

[root_werks]

All 4 must be plugged in to run properly.

On the 2001 the first two must be screwed into the exhaust. The second two you might be able to get away with not having them in the exhaust and simply plugged in, but you'll throw a CEL420 and 430.

Sounds like you got the early 986 2.5 headers. Are the flanges (Triangle ones) flat edges or kinda rounded? Can you post a picture of them?

[snapfrank]

headers that i want to fit on my 986 2001 all 02 are on the manifold

[Orient Red]

On each bank, one of the O2 sensors is supposed to be upstream of the catalytic converter, and one is supposed to be downstream. Many people who put aftermarket headers end up putting the downstream O2 in a new "bung" which is welded into the rear of the catalytic converter (this also requires lengthening the O2 sensor wires. If neither the headers or catalytic converter pipes has an upstream O2 sensor bung, then that will need to be added as well (either to the collector of the header or the first section of catalytic converter pipe).

[snapfrank]

Where should they go ( Remove Manifold) replace with headers

part 26 and 27 we move The o2 sensors


986 2001

[Orient Red]

Where you see the other O2 sensors (item 25, although they only show two in your picture, there are 4, one before each catalytic converter, and one after). Unfortunately, at least on my '01S, they eliminated the O2 sensor mounting points ("bungs", which are essentially threaded holes), so I had to have a muffler shop weld some on...

[Daniel R]

Just a thought, and I welcome anyone who knows more about this sort of thing to correct me, but there may be a way to delete 2 of the oxygen sensors.

Here in Australia, our cars are delivered new with only 1 oxygen sensor per bank, as we do not have 2 sets of cats (the ones on the headers are not there).

Would it be possible to reflash the car computer with the "Australian version" which is programmed only to process readings from one set of sensors and hence no CEL?

What do you guys think?