Hi I am getting about 13 miles to the gallon over the road and around town. My exhaust smells rich.I have tried sea foaming the engine changing the o2 sensor and a tune up and timing adjustment. Nothing seems to work I was wondering if a valve adjustment would make any difference? I have cleaned out the egr I cleaned the exhaust intake where the egr connects to by taking out the brass plugs and running a wire and cleaner through the small port holes. My car is a 1992 honda Accord with 140,000 miles new air filter. vacuum pressure 21, I checked the compression and that was good. Engine idle 750 rpm. I am running out of solutions I do not pull away from lights gunning it I drive normal.I use ethanol here in Illinois and its cold here now when it warms up I get 16 miles per gallon. thank you.

I think you have 2 o2 sensors, no?

Other causes for overfueling would be bad fuel pressure regulator, coolant temp sensor reading too cold, leaking injectors, obstructed intake path (think bird's nest in airbox, really hogged filter, etc), MAF/MAP sensor bad (I don't remember which yours uses)

Check all vacuum lines to any sensors too...sometimes all it takes is a split hose to a MAP sensor to really mess things up...

I am addressing this to moderator jeffcoslacker: I vacuum tested my fuel regulator and it held vacuum I also replaced the coolant temperature sensor.I replaced the map sensor with a used one.Jeff If the injectors were leaking would not the engine keep running after you turned off the ignition switch.I also vacuum checked the egr valve it held vacuum and stopped the engine. I vacuumed checked the evaporator canister and it held vacuum.