I have a 95, 850GLT, non turbo wagon. I've been fighting with a CEL since I bought the car. I keep getting misfire codes, mainly for cylinders 4 and 5. I started with a complete tune up, cap, rotor, wires, air filter, fuel filter, and even replaced the coil. All are VOLVO parts. It still misfired! Then I got a couple of new codes, that the O2 sensors were not working or not present. They have been replaced with BOSCH parts for the front and rear sensors. Still misfires! I bought an OBDII scanner to see what was going on. It tells me there is an open loop fault, and my MAF reading is 0.00 at all times! Oh yeah, I've also already changed the thermostat, cleaned the throttle body, serviced the EGR, ( cleaned out the totally clogged port in the intake), swapped the injector order, found a vac leak at the tree and replaced the missing o-ring! It STILL misfires! I even went as far as getting ahold of another (used) pressure regulator for the injector rail, and another EGR control to try, and still, I have the misfire on cyl 4, and cyl 5. On the highway, the car seems FINE! At idle in park, it runs a bit rough, but in gear, as you come to a complete stop, the engine runs rough! it has never stalled on me though. I even reset the ECU by disconnecting the battery for over an hour! I really need to get this CEL off so I can pass Massachusetts State Emissions! Thanks in advance for any and all your help!