Your car may be running rich because of a dead injector or bad/sticky fuel pressure regulator. Try spraying WD-40 into the FPR nipple by removing the vacuum hose. Then, put it back on and then blip the throttle about 10 times. Take it around the block and see if that helps.
Remove the vacuum hose from the FPR, then simply spray a lot of WD-40 in there. Put the hose back on and start the car up. Blip the throttle about 10 times and take it for a drive. You can repeat the procedure too without harm.