My wife drives a '91 buick regal gs w/ the L code 3800 V6. I put the engine in about 30,000 ago and it has developed a problem. Under load (foot in it going up hill) the car stalls and hesitiates, on the freeway, no problems. Also, the other day when I was under the hood, I noticed a strong burnt oil smell. I couldn't find where it was coming from until I took the air induction tube off up at the throttle body. Thick oil smoke was churning around in the intake. This was right after I pulled the long hill to my house coming home from work. Also, I have a "mass airflow" fault. I replaced the MAS and the problem is still there. I heard that a bad CAT can cause problems like this. Since the engine is fairly new and the car is in excellent shape, I'd really like to figure this out. Anybody got any ideas??