Need more information - what exactly in the electrical system is no longer working? With any battery replacement, it's common to have to reset some items like the digital clock or radio / stereo memory preset stations and settings. Should not need a dealership to do this task.

Who actually installed the battery ? It could be that a fuse or fuses were blown if a mistake was made while installing the battery.The negative battery cable should be removed first and installed last.

The relay is located in the engine compartment relay/fuse box. If you plan to do the work yourself, getting a repair manual is recommended.

The PCV valve is located in the lower right corner of the front valve cover. On both the 2.7 and 3.3L, the PCV valve itself appears to be a threaded stub (M10 x 1.0 mm size threads) that threads into the top of the block as opposed to a cam/valve cover. You can usually just trace them out. There should be two larger diameter (vacuum) hoses attached downstream of the throttle body. One to the brake vacuum booster and the other to the PCV valve. You should find the hose to the PCV valve wrapped in a foam sleeve to keep the gasses warm as they flow through it. PCV valves don't need to be replaced like they used to.
Many engines don't even use them anymore. They've gone to a simple metered orifice instead of the older spring-loaded valve type.

This means the car was in an accident previously - you can check the vehicle title and accident history through the local DMV (Dept. of Motor Vehicles) in your area.
If it were me, I'd avoid the vehicle purchase - too many cleaner vehicles out there for sale on the market that have a clean / no accident title and history.

this means stay away.

Check the flasher and replace it as necessary.

The fuel filter is located in the rear of the vehicle - just next to the fuel tank.

1) Remove the rear seat cushion and the access panel. Relieve the fuel system pressure by disconnecting the fuel pump module connector, then starting the engine and letting it run until it stalls. Turn the ignition off.

2) Disconnect the negative battery cable. Then, attach the fuel pump harness connector. Locate the fuel filter underneath the Sonata near the fuel tank. Disconnect the fuel supply and pressure lines. Remove the fuel filter bracket if your model has one, and then remove the fuel filter.

The fuel filter is located in the rear of the vehicle - just next to the fuel tank.

1) Remove the rear seat cushion and the access panel. Relieve the fuel system pressure by disconnecting the fuel pump module connector, then starting the engine and letting it run until it stalls. Turn the ignition off.

2) Disconnect the negative battery cable. Then, attach the fuel pump harness connector. Locate the fuel filter underneath the Sonata near the fuel tank. Disconnect the fuel supply and pressure lines. Remove the fuel filter bracket if your model has one, and then remove the fuel filter.

I think it is 60K, but check your vehicle owner's manual. The manufacturers usually give mileage and time

Am so sorry that you hit someone with your bike. However be more careful on the road to avoid such cases. However to replace you under carriage look for top quality one. Buy one that perfectly suits your bike. http://4wheelonline.com/StreetBikes/

Try the many on-line auto parts sources, such as; www.autopartswarehouse.com, www.partsgeek.com and www.rockauto.com for the replacement parts, and to compare relative prices.

Would say there is a small drain on battery . Something is getting left on like a small light , radio that doesn't turn off with the key ect . Driving it every day keeps the battery charged up but sitting for a few days it goes dead . Look for something on .