Ok, so here are the facts:

My car: Honda Accord 2002 V6 LX, 292K

The issues:

-low rpms when travelling at high speeds (max about 2.5 going 80, 2 or below for 60: it shoots up to 3 when accelerating but drops instantly)

-instant rpm decrease from 2 to 1 upon releasing the gas (this happens every once in awhile, but I can feel a jolt when it does)

-fluctuating rpms when coming to a stop (dips below idle @ 20mph deceleration and as I stop, shoots back up to 1 or .9 and drops back to idle)

-engine temp decreases at high speeds (45+), whether or not the heat is on (I've watched it drop, not to exact 0 but low enough that I'm concerned)

-rough idle & random misfires at idle

-shaking car btw 50-70 mph (I believe this has to do with steering though)

-feels like there isn't enough power in the engine itself

-oh, and no check engine light: however I did manage to crack the oil filter housing gasket? and leak all of my oil out while I was driving, and I wasn't alerted of this until the check oil light began to spazz out, no rhyme or reason to the blink, just random rapid flashing, so there may be something wrong with the dashboard as well, although the maintenance light is still on from when I needed an oil change @291K (I did it myself and I've been too lazy to reset it)

The mechanics that I've taken it to don't really know what to do and personally I believe they've just given up on checking the car. I'm at the point of just replacing random **** until something gets better, provided it's not that expensive of course. Any advice?

 

I'd start with the simple stuff first before randomly throwing parts at the car. Replacing parts can make the diagnosis more difficult.

When the engine is cold and obviously not running, remove the radiator cap and make sure the radiator is filled with coolant.

Have you had the vehicle scanned for codes? Most parts stores do this as a free service. Do you have a scan tool that can read live engine data?

What parts have been replaced recently?

 

i have checked the radiator fluid under the cap and in the reserve tank as well. Both are full. As for parts, the last thing that was changed was explained to me as the oil filter housing gasket, I don't know the actual name. Other than that, I don't believe that anything else has been replaced that I'm aware of. Other than spark plugs, coils and filters of course

 

The only thing that comes up when I scan the codes is an EVAP code about fuel pressure

 

If you can post the EVAP code that will help. That shouldn't cause your idle issues.

Does your scan tool give you any live readings? Specifically if you are in open or closed loop and the engine coolant temperature.