I have a 2007 Prius Touring
I have a 2007 Prius Touring which I purchased new in Dec2006. Maintenance has been done on schedule by Toyota. Have used Mobil 1 synthetic oil and, perhaps as a result, the car burns almost no oil. Has only 109,000 miles. The check engine light went on a few years ago and based on the code, an intermittent 4th cylinder misfire was detected. But despite extensive analysis by both Toyota and an independent shop, neither can tell me what is causing the misfire (which is barely detectable by shops and has not affected mileage) or how to fix the problem. This issue has prevented me from passing the CA smog test and renewing my registration - not because the car is polluting but because a code is being produced. Toyota has suggested a valve job ($4,500) but does not guarantee that this will solve the problem. CA says that I have to fix the problem or scrap the car which is crazy as it runs like new. CA bureaucrat told me that this engine is similar to Scion engine which had similar problem and cannot be fixed, which I find doubtful. Any suggestions for diagnosis and fix? Thanks in advance for your ideas - I have hit a dead end otherwise.