my pops car is a 86 chrysler 5th avenue 78,ooo original miles. he was haveing stalling out problems last weekend i looked it over and drove it concluded that it felt like a fuel restriction problem, so i changed the fuel filter. ran like a top for 2 days and started acting jerky stalling out at stop signs hesitant at starting off from stopped etc. so yesterday i put plugs in it gapped correctly. old plugs were sooty looking black would rub off on your finger. so i tested it out on highway and it seemed to be better but still not real smooth. today i went over and started it up and with rubber gloves and a plug wire tool i removed one at a time each wire and tried to find a cylinder that stayed the same . all would falter a little with plug wire off. so i put a new distributer cap and rotor bug on and it started up sounded smooth and as i put up my tools to let it warm up a bit before the test drive i told my dad to go ahead and get behind the wheel and i would get in passenger side . he gets in and starts to put it in reverse and it dies again. so i put the second fuel filter on (second time not a different located one) started up fine and when we try to back out dies again wont start again finally starts up but runs like crap coughing and sputtering i saisd let it run like this a bit and see what happens aftwer a bit smokes starts pouring out from under car . i open hood and the crossover pipe is bright orange !!!!!!!!!!!!!! what is this cataletic converter clogged??? did i clog it breaking it open out on the highway last week or is this just something that was happening and it finnally went south???