P0031. Is the o2 sensor absolutely necessary?
 

Morning,

Quick question,

Is the exhaust manifold o2 sensor needed? Please excuse my ignorance, its just i thought the other sensors can be removed during decat. Im planning a full decat and remap in future and really do not want to spend on this sensor if not needed or if its likely to pack in after decat. Like i say im no expert on this!

The engine warning light has come on and its code P0031. If it needs to be there and working then ill have to buy one.

Anyone had much luck with the reliability of fitting second hand as there is one on the forum for sale cheap now?

Thanks for any help.

Afaik all decat pipes should have a fitting to re fit any sensors,I'm not sure if its ok to remove them completely or not,some who knows about mapping should be along soon to answer that one.

yes its needed afaik, which car btw newage???

New age car its needed on the o/e ecu. Not on some of the aftermarket ecu's

Thanks. It's 01 bugeye. Cheers.

just to clarify on an 01 bugeye your front sensor in the exhaust manifold is needed the oe ecu needs to read this to get your afr correct, the 2nd one in the up-pipe isnt needed and the 3rd one the rear 02 isnt needed either.

The front 02 is used for closed loop fueling , if you had it mapped to run full time open loop you could if you wish remove the front 02 ,

Thanks for your help.

So I'll buy a new o2 sensor for the manifold.

How do I fool the ecu into thinking the other sensors are still there when I decat exhaust? Resistors?

Sizes please and where do they go?

Thanks.

Fooling the ecu isnt sensible. Yes it can be done. But this will affect fueling. The best way forward is haveing the ecu remapped.

Ok, maybe I misunderstood?

So I can remove cats but keep the sensors in place and wired as standard?

Yes , and will then need it mapping to make sure it's all ok and get the benefit from the decat exhaust