Hi guys I've got a v2 sti lump I've bought a decat managed to talk the old pipe off however the bolt has rounded off for the oringal sensor, can I temporarily run it without an O2 sensor or is it a big no no ?

Thanks

 

I wouldn't. Will run rich. fowl everything up.

 

If its a v2 your lambda sensor should be in the headers mate on drivers side....have a look and this sensor which u think is a lambda i might possibly think is acc your cat on fire sensor which in this case with a decat is grand to run without, although just make sure to get a bung for it!

Regards, Anthony