I did a little highway driving and it was fine in the beginning i parked a the beach, and proceeded to swim. After I was content. then my girl and i hoped in the blazer and fired it up and pressed on the peddle and it was kind of sputtering. it does not want to go it just feels like it is sputtering on the beginning when I put her in gear and try to go. it also runs really hard. I just drove it home ad i do not dare drive it right now. it will die. What other info can I give you hmmm? The engine is good it has be running good for 1/2 a year now ever since I put it in until now it is a 406. You think that something might have blown back in the exost. I replaced the spark plugs. Well that is all that I really have to say right now if you need any other info so that you guys could help me just ask. plz help me out i would love to get the blaz ruing again so I could do some crawling.