I have eliminated my main cat but I want to get rid of the fronts. I have seen several aftermarket downpipes and some have flex tubing and some dont. I have a friend that owns a muffler shop that would build me an exhaust but I dont know if he can do the flex part of the pipes. Are the secondary O2 sensors needed or is it safe or recommended to just get a O2 Simulator from 3SX. In building a custom exhaust system are there recommended web sites to help with this or does anyone have information that can help me. Thanks.....

 

The 02 sims and running no flex is fine.