Nissan Repair: Replacing Spark Plugs, nissan sentra, commuter car

Question
QUESTION: Hello Calvin,
I have a 2001 Nissan Sentra SE with a little less than 170000. miles on it. I bought the car with about 80 on it.  It's basically a commuter car with 95% of the driving on the highway.  Recently it started to act up on occasion(hard starting).  Yesterday, I couldn't put it in drive without it stalling.  Anyway, I haven't changed the plugs since buying the car and suspect that they are fouled up.  I bought new plugs and hope to save the wires. I've never seen these type of wires with a shaft on the end.  I assume you'd just twist and pull like the wires on my departed 89 Mustang?  Anyway, just  thought I'd ask before yanking on the wires.  I don't want to replace them unless I have to especially at $100 bucks here in Canada.

Thanks,
Tim

ANSWER: Hi Tim -

Yes, you are correct. Just twist and pull straight up on the plug wire boots. Is your sentra running rough (missing) at operating speeds also? If not, then I don't think it is the plugs or wires, although at that mileage interval the plugs should be replaced.

This may be a fuel issue. Do you have a check engine light that is on?

Let me know -
aloha
calvin

---------- FOLLOW-UP ----------

QUESTION: Hi Calvin,
The car runs fine once the stalling corrects and it doesn't happen all the time.  I notice it when it's damp outside although I don't see the wires arching.  There is no check engine light when it happens but I do smell unburnt gas.  Yesterday was the worse cause I couldn't put it in drive without a stall.  After fooling around with it for about 15 min, I assume it was warm and maybe had burned some carbon off, it was fine.  It only happens at idle speed and not all the time.  Made my daily 80 mile commute and it ran fine.  Every so often I may get a 440 Evap Canister code but not recently.  I think my gas cap is going bad.  Is a tune up the first thing you would do considering the car hasn't had one for at least four years?

Thanks,
Tim

Answer
Hi Tim -

Yes, I would recommend that tune up. The stalling could be many things, however since there is no engine code, it eliminates a few.

Don't forget to replace the cap and rotor. A lot of times there is carbon tracking.

Hope this helps -
aloha
calvin