HELP!! Car runs horribly and cant get rid of these codes,

I'm not really sure where you're at on this, or if I'm going to help at all, but I would like to point out a few things. You first asked a question as to how you back probe a harnes. The easiest way is to sneak into moms sewing kit, steal a small stancion pin (little pin with the head on it, not one you thread with) and push that up into the harness from the back. Ohm your pin out with the metal connector on the other side to make sure you have continuity (0 ohms) and then you're ready to measure (simply put, you stick one multimeter lead on the pin you stole from mom and one on the metal pin in the harnes; should read 0 - .1 ohms, doesn't mean you have a ground, just means you have continuity). Second, for your application it's not really important whether you use the black or the red wire for chassis ground. By Chassis ground I mean when you measure your tps voltage (or whatever you're trying to check) against the engine block. Don't use your battery, use a solid screw or the cast iron of the block for your ground. Check all your connections against haynes to verify good voltage. If you think you have a ground on something then it should be fairly easy to identify. For instance, if there were a ground on the reference lead coming from your TPS (the wire with the changing voltage) then it would read close to 0 volts (0-.2 volts I think could be considered a ground if thats all the range you get out of it) From this position you would disconnect the harness (after turning the car off) and check to make sure you have a ground on the wire. You can ohm this fairly simply by putting one lead on the block and one lead on the harness wire (should be 0 ohms with ground fault; make sure you're not trying to read voltage with the ohms selection and vice versa, it's easy to get ahead of yourself and forget to switch the meter). If the problem goes away and you don't have a ground on the reference voltage wire then reconnect your TPS. If the symptoms repeat then replace your TPS. The same should hold true for just about all the other sensors you have in your car. A little word to the wise. 99.9% of the time when a circuit dies, or breaks, it developes an open, not a ground. So if you're positive you have a ground on a wiring harness in your car, it's most likely because something moving has worn or stripped away the insulation somewhere. This most likely causes an intermittent problem, and not a constant one. Keep this in mind. You'll do fine. Just a few guidelines when troubleshooting. All your sensors have a ground wire, don't let this throw you, it's how they work. All of them also have a power wire, usually 12 volts. If you turn the car on and one wire is ground, one wire is 12volts (polarity doesn't really matter, your car isn't going to switch from +12 volts to -12 volts because something broke) and the other reads a changing (or reference) voltage then you don't have a bad ground. You might have a bad sensor, but not a ground. Check this changing (reference) voltage against haynes. Now Haynes should tell you which wires to look at, and some of your sensors will have more than 3 wires, but if you have a low voltage coming out of a sensor, and haynes says you should have x.x then I would start with that sensor.