Arno,

Our cars have two O2 sensors but they are one right behind the other (again something Volvo chose to do to confuse the rest of us) So there are no problems with O2 sensors. The first catalytic converter which you mention has been placed there to help the engine warm up faster. For personal preference reasons I chose to keep this one because I already own a car with straight pipes and glasspacks and it's a pain in the arse (LOL!) to get the thing warmed up in the winter time, granted the S40 would still have another two cats to help it warm up, but it was that and the fact the main catalytic converter was just there ready to be cut off.

Hopefully the straight pipe will be something that goes into production and we'd like to make it as easy and inexpensive as possible for a customer to have this modification made to their car.

I think I actually have some close-up pictures of the two sensors by the way. I'll dig around my hard drive this weekend and if I find them i'll post them up on the website. Have a good weekend!

Carlos