Hello I'm looking for advise for my sisters 03 pathfinder she bought to use as a second vehicle/winter vehicle last November. Overall the vehicle is in great shape it was garage kept it's hole life and only has 86,000 miles on it. After having it a few months it started running poorly and she took it to her local garage and was told the cam sensor was gunked up with sludge. They replaced the sensor changed the oil and it ran fine for 3 more months until the same problem happened again. She was told the sensor was sludged up for the second time. I have always been aftraid of solivent flushes but apparently something needs to be done to address the sludge issue. The vehicle isn't her daily driver and she only put 5000 miles on it since November. Any suggestions?