What is causing my Astro van to lose acceleration

Over the past few months, my van has gradually been losing its ability to accelerate. It has not only been more difficult to accelerate; it has also been harder to get to and maintain a higher speed. And the speeds in which I am able to reach have been steadily decreasing. The other things that have been happening during this period is that, in addition to the normal knocks, the loudness of the engine – like someone who doesn’t have a muffler-- has been getting louder, and there has been a very noticeable fuel type of smell, or an exhaust type of smell, that I can detect almost as soon as I start it up, and this has also been getting progressively worse. Along with those things, it has been stalling out, especially when backing out of a parking space, more and more. The car does leak a little oil from somewhere and it also leaks anti-freeze from a hairline crack in the block, but it is leaking on the outside and not going into the oil. If there is anyone out there who thinks they might know what is occurring, or if they think that it can be fixed for under $200, or who wants to buy the van off me for $900, let me know. Thanks, Jeff

What engine? AWD or no?

Off hand, it sounds like a bad catalytic converter to me. Sounds like it could also use a tune-up, which might be why the converter went. Does the van use much oil?

The engine is a V6, 4.3 Liter. The engine was replaced less than three years ago. I had a head gasket replaced unnecessarily about two years ago because some mechanic told me that it was leaking from the head gasket area, but the mechanics who worked on it said that there is a hairline crack in the block, and that is where the anti-freeze was coming from. But it only leaks anti-freeze after I park the car. I haven’t changed the oil recently. It does leak some oil, and so I am not sure if it burns alot of oil. It is hard for me to see where the oil is leaking, but I can see it on the driveway where I park. I also had the transmission making clacking noises, and the transmission mechanic charged me $700 to fix it, but it never drove the same after that. Those two repair jobs happened around the same time, and so it is difficult to figure out which mechanic screwed up the van the most; maybe it was the junkyard mechanic who put in the engine for me for only $1500. My situation is such that I can’t afford to buy another car or to spend more than $200 to repair the vehicle. And when I say repair it, I mean to only fix the current problem, not all of the other problems which I was able to pass inspection with year after year. I spent $8000 on the vehicle in maintenance and repairs since I bought it in April of 06 for $400. There are a lot of new and fresh parts in the car. If there is any mechanic out there who enjoys working on Astro vans and fixing them up to their liking, please let me know. I live in the Philadelphia area. It looks alot better, inside and out, than it runs. How’s that for a sale pitch?

oh yeah, it’s awd too. Most Astro vans had 4.3 liters and awd. Anyway, there you go.

but i just remembered, it is not actually awd drive anymore since I had the thing cut off. The suspension drive bar — or whatever you call it, was cracking and falling down on the framework, and so, I had the mechanic cut it off. now, it’s a front wheel drive. Ok, that’s it. That’s all of the info I am giving. I am now waiting for the miracle cure! for under $200.