Hi, I have a 4 cyl 04 Manual Sonata, I have been having major engine issues for the past year. In July on 12, I replaced all the spark plugs and plugs, only thing that wasn't replaced was the gaskets. I still was in constant power loss and rapid fuel consumption. I replaced the fuel filter, after that is when all hell broke loose. 5 miles a gallon and variable power issues. Took it to the shop, no engine light had coded and this was in Nov of '12. After 2 weeks in the shop and replacing the catalytic converter, and the gas was still running lean. They replaced the mass air, o2 sensor, spark plugs, injection system flush. After all that, still running lean, I suggested they look at an issue that occurred when I I first got my time belt replaced. The Crank Sensor Blade had started to move, and the pin wore a pattern in the metal. When they checked, low and behold it did it again. After replacing the part, and the belt, they returned the car to me. The Car ran louder and the best I could describe angrier. The exhaust seemed to roar under the driver seat. In Jan it had its first ever coding even on the computer. The reading came out to be p0302, due to schedule I wasn't able to take it in to the shop. Feb 10th, the car starts to Misfire like crazy, the preemptive warning I felt was that the engine in Idle was really bad, huge imbalance felt. A mile later the car starts to buck, after 5 -10 mins with the engine off, the car worked fine for a few more miles. The misfire got so bad that the engine shuts itself off. I took it into the shop the next day, they said they couldn't find the issue, but thought it was the ignition coils. Handed me the car back after to switching the coils from 1, 4 to 2, 3. 10 miles later boom, it happens again, I replace the coils, and its still having the same p0302 issues. Any ideas, im not wanting to take the car back to them anymore, even though the work is warranted, I dont trust them very well.