Chrysler Forum - Chrysler Enthusiast Forums - Low compression on cylinder#5.I have 2 different diagnosis!

Hello all,
I have 2010 Chrysler 300 which has 58,000 miles on it. Last week the check engine light came on and since then the car acceleration started to decrease (especially on the highway). I went to my mechanics and he said that there is misfire on #3 and #5 and you need to change the sparks and the fuel injection to fix the car. After he changed them he called me and said there is still misfire on cylinder#3 and he believes that the problem is with cylinder itself. So, he said that he need to take the engine apart and look to the cylinder and it gonna cost around $2000 (more than 12 hrs. labor). I got shocked!!
Then I went to the Chrysler dealer to ask for another opinion. After 4 hrs. the service manger at Chrysler called me and said that the problem is with the Power control module not with cylinder!
He said that the PCM costs around $900 and your warranty will cover it (he said I will help you even though your warranty has expired) and he asked me to pay just $116 for the labor.
I do not really know who to trust here and I am afraid that PCM will not fix the problem!
Is it common that the PCM can cause misfires and low compression?
Thank you guys