I have a one owner/driver 2006 NA PT. It has no rust and has recently had a tune up and new battery. After the first start of the day, when I start it, it turns over at about 450 RPM without the usual bump up in RPM's upon cranking. Usually the car will catch and start but sometimes it will misfire for about 30 seconds and then even out. It will throw a code P300 - P304. Otherwise it runs great. It has been well maintained and has 162,000 miles on it. Thanks for any help with thus.