So many codes on my 2000 986 project car. Any idea of possible root cause?
 

Is anyone able to tell me if there might be a root cause for all of these:
DME fault codes?
P0139 02sensor ageing behind cat c, bank 1
P1128 Oxygen sensing adaptation, idele range, bank 1
P1130 Oxygen sensing adaptation ideal range, bank 2
P1126 Oxygen sensing adaption, lower load range, bank 1
P1133 Oxygen sensing adaption, lower load range, bank 2
P1117 Refer to service manual
P1119 Refer to service manual
P0446 Shutoff valve, activated charcoal filter (function)

HBA Control system
1 Engine path left
2 Engine path right

Biggest clue is the P0139 code.
When an O2 sensor ages or gets old the signal from them slows down. When that signal slows to a certain point it triggers the code.
So all your codes except the PO446 are O2 sensor codes. they are for the O2 sensors in front of the Catalytic Converters.
I would change both of them out for new ones.

If you continue to run with faulty O2 sensors eventually you Catalytic converters will be destroyed.

PO446 there is an issue with the Evap shutoff valve. Make sure the wiring to it is good and replace the valve.

Can't help you with the HBA

How many miles on the car????

Oh. Hey... Hi.

Welcome to the forum.

I misread this post the first time I looked at it.
The P0139 code is for an aging sensor behind the Cat on bank 1.
Nothing you can do to fix that except replace the sensor.
All the other codes are for Pre Cat O2 sensors on both banks.
Some are rich threshold limit codes and some are lean threshold limit codes.

I need more information on the car to be of any help
like
Year?
Miles.?
Is it all stock??? or are there modifications???
Any recent work done to it?