Friends,

A 1995 Merc Grand Marquis, 213,000 miles, NOx 2700 at 15 and 2500 at 25mph. MIL is on, codes for all four O2 sensor heaters. This thing is a pseudo OBD2 vehicle. The EGR is totally plugged. The PCM driver has failed so none of the O2 heaters will li... Login to read more.