I have an 89 GT, 5.0 with t5 manual. Just got the car back from my mechanic and on the drive home I noticed a faint burning plastic/rubber smell. He had just replaced the water pump gasket so i figured he may have gotten some rtv on the header so didnt think too much, then a check engine light came on and stayed on. Also at least 3 times the car stalled in between shifts while driving 40 mph.. I am not able to contact him due to the long weekend, but the car was running perfect before this.. what should I be looking for here? I cant seem to find the source of the burning smell under the hood