To sum it up, I installed some Kooks long tube headers with high flow cats on my Jeep the other day. I was in an out of the shop and trying to run a few errands and dealing with customers so I must have stepped out when my mechanic disconnected the O2 sensors. I know all four O2 sensors were transfered over to the Kooks midpipe to the proper locations. The only thing I am unsure of is the where each O2 sensor plugs in. On the passenger side near the top of the trans there are 3 O2 sensor connectors. The 4th one is on the driver's side so that one I am pretty certain is in correct. I am getting a "bank 2 too lean" code and check engine light. I am guessing the front and rear O2s are switched. Is there any easy way to tell which is which without tracing all the wires and looking up the colors in the fsm? I'm trying to have my mechanic fix this while I am on duty. Thanks in advance.