Engine Performance problem
1999 Buick Lesabre 6 cyl Front Wheel Drive Automatic 115000 miles
I have been driving with the 440 code (exaust leak) for several months w/ no problem. Today car started missing when I tried to exelerate and threw a 300 code(random misfire). At the same time started smelling like rotten eggs. Brought it home, shut it off. Had a very hard time getting it to start again, but when it did, white smoke billowing out of tailpipe that smelled reminiscent of burnt plastic. Shut it off again. Later went to start it. Will not start at all now. Maybe my exaust leak caused the mixture in the exaust to clog up my catalytic converter? Have also read online that it could be fuel pressure regulator? Any ideas?