I have a 97 Jeep Cherokee that has no problems until a week ago. A week ago I wanted to do a tune up on my Jeep because I believed that the previous owner didn’t do a tune up for a long time. So I went to a local auto parts and got double platinum spark plug and premium spark wire set. I changed the old and put the new ones in. Then I went to turn on my Jeep Cherokee and my engine started shaking. I looked under the hood and check my distributor I saw it was beginning to be worn out so I bought a new one as well cap and rotor as well. It still shook but once I got the firing order on the wire set on correctly, my problems just got worse. The next day after all this my Jeep started to jerk once I pressed on the gas pedal and began to stall out. So I get a auto scanner and it tells me p0320 code which was something for the crankshaft position sensor so I replace it yesterday.At first it ran fine but I suddenly it but then it began to jerk like crazy and my gas gauge was flickering and so was my rpm gauge. After all this my Jeep Cherokee will start but it sometimes crank and run but once it starts to run it start jerking like crazy. I mean come on all of this for a tune up for a 97 Jeep Cherokee Xj. Help me plz and tell me what is my problem and how I can fix it. You may ask more questions.