u didn't state the year ...but ..there's a good chance that this will affect the ses light....is your o-sensor in the cat? if it is its a definite yes ...if its downstream the you could be alright .. there are many cat manufactures and like any other product...some are better than others.......we install hy-po exhaust systems everyday...and some types have given customers fits over this same issue...we've tried the spacing method (with limited success) we understand that they make a wiring kit for the o2s to take care of this issue ...and have ordered them but as of this week we haven't received any.......so their funtionality is unknown to us at this time