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Modified Porsche Cayman P0056, P0421 Code questions- kinda long
I just finished installing a twin turbo system on my 07 Cayman, prior to that it was modified with headers/catback/intake and a tune and ran perfect with no CEL's.
The twin turbo system comes with a tune for the larger injectors, etc. and tunes out the secondary O2 sensors- primary O2 sensors, plugs, coils are new.
The car runs very well power wise and fires right up on cold start but I get a slightly surging idle after fully warm & then codes P0056 & P0421 on warm restart with a slight hesitation in the restart (normally fires up instantly). I figured this may be due to an intake leak as there is quite a bit of piping for the turbo system after the MAF so I used a smoke machine and found a few intake leaks which have been fixed. Idle improved somewhat but I still get the CEL's on warm restart.
I have a code reader that gives some live data, these figures are warm at idle:
B1-S1 & B2-S1 bounce between about -.02 and .1 MA
B1-S2 bounces between about .105v & .890v, B2S2 remains constant at about .455v
MAF about 3.9 to 4.5 g/s
Fuel system 1 status: CL
Fuel system 2 status: CL fault
Long term secondary O2 sensor fuel trim is 0 on both banks
Short term fuel is about 2.3 B1 & -5.2 B2
Many thanks if someone can point me in the right direction to solve the issue(s) or any more diagnosis instructions
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