Toyota Repair: Engine, real tune, scantool

Question
Hi I have a 96 tacoma 4cyl 5spd.

I noticed the truck was running high rpms while on the freeway and when i got off freeway i noticed some strange straining noise and the truck was kinda shaking. After stopping at a light I noticed when i started to drive off the truck kinda chugged and was having a hard time.. shaking and kinda surging. When i got home i noticed a fuel smell. Checked the oil and it was almost out so i added 3 quarts ran it at idle for 10 min and test drove it. It ran a little smoother and quieter but still hessitated when changing gears and speeding up. Truck seems to have lost some power as well. Its been 3 days and I drove it a little today.. its not as bad but still same problems when taking off. Check engine light has also come on. It has been about 2 years since its last real tune up.. What do you think is going on? Im going to do small tune up tomorrow.. oil change spark plugs and air filter if looks bad. Do you think its the clutch going out or just needs tune up? someone suggested it might be fuel filter or pump going out.. Any advice will be most helpful. Thank you  : )

Katherine

Answer
Since the check engine light is on you need to have either a toyota dealer or any other shop hook up a diagnostic scantool to retreive the trouble codes stored in the computer, once you have that information you can get back to me for any additional advice.