Rich fuel mixture in exhaust pipe please help

after jumpstarting my coworkers car my 94 ford mustang 3.8 v6 now wont go above 40 miles an hour and has a rich fuel mixture coming out of the tailpipe. i fixed the spark plug wires and new plugs. still the same. please help if you can.

Check the fuel pressure regulator. If the diaphram in the regulator developes a leak, liquid gas will be pulled into the intake manifold via the vacuum hose.

Tester