Hey guys I have a 2002 gt in the shop. It had 18 codes! we got everyone fixed except for the p0135,141,155,161 code which show to be heater circut fault for all the O2 sensors. Im guessing it to be the circuit that heats them up prior to starting the car. I seriously dont think that all 4 o2's are otu so where do i start? anyone ever had this problem? Hope you guys can help. Thanks

 

Anyone?

 

Here's what the '03 shop manual suggests...