I bought a 2004 sonata 4 cyl with 7k miles. The check engine light came and I get and got a diagnostics and came bad with 1 bad code and 1 pending. The bad code was my EGR Sensor and the pending one was my knock sensor. I replaced the egr valve and the light went off. About 2 weeks later I was driving home and my light came on again and before I made it home the car was bogging down not really getting fuel. A small click started that sounded like it was coming from the throttle area. Soon after the car heated up quick so I quickly shut the car off. I let it cool down and then got jumped off and got about 1/4 a mile down the road when it began to heat up again. Again, I pulled over and roadside assists came by and put some water in the car and tried jumping me off. The car would eventually fire but the RPM's would drop and the car would die unless I was giving it a little gas. So, at that point the car would not stay started. I got the car towed to my house and it will not even turn over at all. Since then I went and bought a new knock sensor and found it where it screwed into the block but the old sensor's plug in was ripped off. So now I cannot find out where the other end of the knock sensor goes? And what would be causing my car not to start?

. Remove and fully charge, or replace, the battery. Most auto parts stores will charge batteries for free. Clean battery terminals and cable connections. Examine the cables for hidden corrosion and breaks. Jumping a modern-day vehicle is very dangerous. Voltage spikes and arcing can fry the ECM, alternator, and selected sensors.

. Check all under hood and under dash fuses with a test light or multimeter. Be very thorough.

. Check for codes again.

. Check for spark. If it's poor quality, focus on the Crankshaft Position Sensor and coil.

. Check for fuel. Can you hear the fuel pump run, when the ignition switch is turned to ON?

. Go over the cooling system. Radiator passages may be blocked by phosphate scale. If so, replace the radiator and refill with a 50/50 mixture of the proper antifreeze and distilled water.