Q: Car jerking and gas smell and loud noise

The most important issue is the fuel odor which signifies either a leak (vapor or liquid) or engine misfiring. A leak is potentially disastrous, especially if you park in an enclosed space such as a garage where vapors can accumulate. Misfiring will cause the catalytic converter to overheat. I would start with a fuel leak diagnostic. Once the leak is resolved, the problem with the engine operation would be handled. Causes of rough operation range from fuel system to ignition system, air induction, sensors and so forth but you could even have contributing factors such as faulty motor mounts. The exhaust leak and oil change should be resolved last. One caveat though: if you do not elect to have any repairs done, it’s NEVER a good idea to drive a vehicle that has a known exhaust leak due to the potential for carbon monoxide poisoning. So, in a bit of a twist, if you are not repairing the engine (the rough operation), fixing the fuel leak and the exhaust leak become the priorities. If you are electing mobile repair, the dispatched, certified mechanic who handles the fuel leak will be well qualified to deal with all other issues (the rough operation and the exhaust leak). If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.