My car is giving me trouble going up steep hills. It feels like I am towing a ton or gravel and won't pick up speed even when floored. Otherwise it drives fine. I have done a full tune up - Drained and replaced all fluids. Replaced my transmission filter, oil filter, air filter, plugs and wires are all new. My Timing belt was replaced less than a year ago. After I take the car up a steep hill - which again it doesn't like - it sometimes even bucks a little during the incline - I smell a burning rubber smell and something from underneath the car does smoke - near the beginning of the exhaust pipe. Can someone tell me what the problem might be?
If the engine runs smooth, not bucking or shaking while you initially accelerate, the most common causes would be a clogged fuel filter or a clogged catalytic converter. You can remove the fuel filter and try to blow through it. If you can't, it's clogged. You can also go under the car and bang on the catalytic converter (not while hot). If you hear stuff rattling around inside, it's probably broken up and obstructed.
If the engine is not running so smooth, it may be a bad ignition coil pack (and/or ignition wires). The system is comprised of 3 coils, and each one fires 2 cylinders. So if one goes bad, you're running on only 4 cylinders. That would cause an extreme lack of power and overheat the exhaust, explaining the smoke.
The power loss can be caused by a bunch of other failures, but these are very common and a good place to start.
Let me know how you make out.