Test pipes VQ35DE PM35

[NicPM35]

Say someone was to install test pipes (yes I know they are a no-no on the roads), would they throw the ECL? 
A couple people on 350z forums say they get the ECL and some don't.
Will the O2 sensors go out of whack and make the car run lean without a re-tune?

[Duncan]

what on earth is a test pipe? Is it a cat-less exhaust?

[NicPM35]

Sorry been reading too many US forums. Cat delete pipe basically 

[Duncan]

Well I don't have first hand experience with VQ35, but on VK56 which is very similar motor and ECU, error codes only appear with flange sealing problems, not from removing the cat. I suspect people confuse the 2 because they have to undo the flanges to change the pipe, and just see the error afterwards.

Just use new nissan gaskets rather than the cheapies generally supplied with a kit and you'll be fine.

I initially had ECL after changing over, but retorquing the flanges after a few heat cycles cleared it...