'93 Ford Taurus, Need some help here folks :)

Boy, where can we start?

Ok, I have a 1993 ford Taurus (no sho - what ever that is, I suspect a higher performance engine?) and I have a few problems. I shall list them and explain the best I can. Sorry if some of it's jittered... I am not much of an auto guy, but love to (and financially have to) do things myself as much as possible.

here goes.

what's new on the car

+spark plugs (gaped to spec .. or the higher gap of the spec, it said .4 - .6 ? Maybe .04 - .06. anyway, it was a range, and I did the higher of the range. - is that bad?) +radiator - boy, that was fun * flushed / rinsed well before installing. +thermostat +starter +trans filer +air filter +O2 sensor +Exhaust (pipe and muffler- not the C-Converter) +Windshield wipers (though my spay doesn't work)

What's still needed - but I don't know if it's worth it.... Struts- need these pretty bad, little wobbly when going 60ish. Trans. ?

1. There is a VERY loud rattle coming from under my car. This is MUCH more noticeable when the car is cold and/ or put in gear with the break on - and even when accelerating. I would say it is at it's worse when cold and in gear with the break on. Now, by rattle... lets see.... I mean it sounds like there is a huge rock in the exhaust or something. Yeah, I checked lol. When I was under the car I tried to listen the best I could. It seemed to be coming from around my trans. pan. Not so much by the oil pan. This has done this since a week after I bought it (which was a year + ago). About 3 months ago I replace the trans. oil and filter and the oil is at proper level. Didn't change the rattle sound though. I have a new exhaust as well- muffler rusted out. I asked them (Midas) about the sound... they just said (yup... hmmmm) and shrugged. I thought that meant "don't worry about it". Maybe it meant "I don't want to deal with that".

These two might go together...

1. Another noticeable thing is my MPG. I get roughly 19MPG. ick!
2. When I start my car for the first time, it revs up and down. There is some smoke throughout driving it (but it's also getting cold now her Sterling IL) but more exhaust smoke than I should see, I think. The smell of the smoke is nothing suspicious- hope the gasket isn't hurt

*(it used to smell like gas- but that is no longer the case since I have replaced the O2 sensor about a week ago). Then, it seems that the idle is much higher than it should be when it warms up and stops it's revving. I have no rpm gauge but it's definitely higher than 1000rpm. I cleaned out the air intake and put some injector cleaner in the gas tank (supposed to be the good stuff- don't remember the name but it was a white aluminum can). I also cleaned the Idle Air Control Valve as I was told to - but slowly putting cleaner into the vacuum line hooked to it. *** I did this BEFORE changing my O2 sensor, didn't want it to damage it. After the cleaning, the revving up and down is much more stable, but the gas mileage is horrible, and the rattling is bad to.

1. This is new this week - When I stop, the engine idle mostly fine, smooth at least( it used to stay at the high idle until I replaced the O2 sensor. After about 1-2 mins it "shifts" or feels like it does, and that rattling is much louder again... then after about 1-2 min of that, it goes back were it was- quieter and smoother. If I let of the break when it's louder (after it feels like it shifted) I will actually be accelerating up to 15 were it will then shift and go to about 20!!! This is all without the use of the gas pedal! Now, if I let off the break during the quieter idle at a stop, it seems normal, just goes along at around 5-7mph. I was thinking maybe it's adjusting to the O2 sensor or something... but maybe not. Other shifting things to note- 1. It has always "slipped" a bit between 1 and 2 gear, but only if I am accelerating a bit fast 2. Lately, if I accelerate up to 15 and let off the gas, it shifts to 2nd quite hard on it's own. It does the same when downshifting after a cold start between 1st and 2nd gear. - I'm suspecting my transmission is going to be short lived from this point... but maybe it's something else... like a sensor?

2. Perhaps this is much of the problem as well... I can hear a whistle form the engine compartment while the car is running. It's been getting a little bit louder in the past 6 months and I am almost positive that means a vacuum leak, I know that can have dire effects on the cars running- but not sure how much. I looked everywhere without taking all the hoses of one at a time. Perhaps that's what I should do? If there's any tips on that process or how to detect a leak, please pass that on as well.

So there I we it... It does start like a champ every time, it goes, but there are those things that either need tweaking, cleaning, fixing, or just drive it until they die away lol. Mainly, I would like the MPG to be much better and I feel that it being that bad is a sign of something needing fixed or cleaned. I also don't like the shifting, but perhaps it does that due to the high idle? And the noise.... Who knows- I have heard some say a fuel line can do that... but I just don't think so, not that loud. But is has been limited (up to recently) to cold weather. It is definitely many times worse in the cold, though it does it all the time now.

Any help would be a god-send. I really appreciate ANYONE who takes the time to read and or reply to this post. It's a lot- but I wanted to be as accurate as possible and mention as much as I could. Time I can make happen, but money is tight as I am finishing my college this year. That is why I'm trying to hold on to the car. I hope the tips I get push it for another year or more :)

THANKS AGAIN FOR READING / HELPING :)