Nissan Repair: 2003 Sentra Spec V slight surging, evaporative leaks, charcoal canister

Question
Hi Von,
First, thanks for your time. The problem: the car has thrown some codes in the recent past regarding "evap leaks", both "small" and "very small", 0442/0456. Until now I thought that it was probably the fuel cap so I cleaned off the filler neck and cleared the codes. It has been reappearing every 1-3 weeks though. However, I have noticed some occasional, very slight surging lately. It usually occurs on the highway at constant speeds. At this point it's really just an annoyance. My questions: Do you think the incidents are connected? What could be causing the surging? Could this develop into a serious problem and can an "at home tinkerer" like myself do anything to resolve it? Thanks again Von.
Shane

Answer
Shane,

The issue is most probably connected with the surging.

The evaporative leaks have to do with the fuel system.  Under the car there are hoses that connect the gas tank to the engine and the charcoal canister.  There is a vent valve that allows gas to go from the charcoal canister to the gas tank.  It is a sealed system for pollution prevention.  Also it is good for you since the gas does not evaporate.  More gas to burn and less going into the atmosphere.

Back in the 2003 time frame there was a recall regarding rotten hoses and bad clamps on Nissan fuel systems.  The time is well past for Nissan to do anything for you.  But, this gives you an idea that you need to put the car on a lift and inspect and replace any rotten, soft or suspect hoses.  Also, look for loose clamps.