Today when I was driving my car it began to vibrate loudly and then it acted like it was going to stall. It sounds strange when it is running and when I press on the gas, it is sluggish, very sluggish

Yes indeed.

You want to get the vehicle drive shaft (torque tube) checked for any loose end play... paying particular attention to the "U-joint" area.

As bad as you are describing it it sounds like you are really close to dropping your drive shaft...

DO NOT work on this yourself if you are not TOTALLY familiar with good jacks... jack stands... wheel chocks and have a level work area available... also keep in mind that while your TRUCK may be in PARK... that is only as stable as your drive-shaft.

Don't get between your truck and a hard place until you get that DRIVE-SHAFT fixed...

Another hot tip... if you are going to the trouble of removing the drive shaft... replacing both "U-joints" would save money and time in the long run.

Be safe... work safe!

http://www.rangerforum.com/threads/u-joint-replacement.6756/

UN-Edited response via comment line:
Oh yes indeed.

It appears that the Ranger can come in many different configurations... but the rules of home trouble shooting are to go after the cheap and obvious probabilities FIRST, (loose lug nuts) then on to the rear-end... CV-joints (if you have them)... wheel bearings... finally back up into the transmission.

Seriously... look that drive-shaft over:

Have an assistant hold one wheel while you move your rear wheel... while you are watching the drive-line... the offending u-joint should reveal itself by showing some free-play.

These should be very tight...

Perhaps then when you look more closely you will see the HORRIBLE (chocolate) brown color of oxidized iron... ALWAYS an imminent sign of DANGER anywhere on your vehicle.

The u-joints can be pretty bad... and the vehicle still run... but once that drive-shaft drops your parts costs will escalate vigorously (assuming everybody survives (my drive-shaft didn't... but mine did NOT warn me (silent failure)).

Please do have a look at the URL I posted with my first reply.

Be safe!

go to repair shop urgently before its too late............

run the fault codes to find the problem
it could be a vacuum leak from a hose fault

http://ricksfreeautorepairadvice.com/check-engine-light-on-part-i/

if you can`t remove starter take it some where and have it removed to check it out.I think your`e on the righ trail.The cable the no starts the hammer trick all sound like starter good luck

new alternator and put battery on charge as well

sounds like transmission is bad

You need to take the car back to the place that did the exhaust work. What you are hearing is the exhaust system (pipe, muffler, etc.) touching the underside of the car. The exhaust system is mounted along the underside of the car with exhaust hangers (usually made of rubber) also called insulators. The reason you don't hear it when going is because when you step on the gas the engine torques causing the exhaust system to move away from what it is touching.

you can check the wheels make sure there on tight and make sure you tie rods and wheel bearings are good

has the tps (throttle position sensor) been replaced