I'm having a problem with my 1996 3.3L, p0171 System running too lean bank 1. I have cleaned and replace MAF sensor, Replaced the fuel filter, coil, wires, plugs, EGR, all four O2 sensors, cleaned the injectors, and there are no vacuum leaks, now my mechanic is telling me it has to be the coolant temperature sensor. The car is acting like it is missing and running rough, emission testing is in about three months and I'm at my wits end. Someone please help, can the coolant temperature sensor cause this problem?