Nissan Repair: 2002 Nissan Altima, 2002 nissan altima, nissan altima

Question
Hi Calvin,
My 2002 Nissan Altima has 60,000 miles on it. It sometimes shakes when going at low speeds, and recently the check engine light came on. I took the car to a repair shop and they replaced the spark plugs, which didn't work. They then replaced the #3 coil. Tbis seems to have worked, as I just drove my car to my job and it's running smoother than it has in months. However, they told me that when they removed the engine cap there was a leak in the intake. They said that when they replaced the cap, the leak stopped. They said that they didn't think it was a problem if the leak stops with the cap on, but that if the check engine light comes back on I may need to take it to the dealer.

What could be causing this problem? Is it more serious than the mechanics suggest? And approximately how much would it cost to fix if it is serious?
Thanks!
Kate

Answer
Hi Kate -

Best thing to do here is to research what made the check engine light come on. There are literally hundreds of sensors that "report" to the car's computer on a regular basis, and if any one sensor is getting a wrong reading, it activates the light. So replacing this here and that there is only guesswork. Try going to an Autozone, I think they will download the codes for you free. This process is called ODB (On Board Diagnosis).

Once the codes are downloaded, get them and report back to me and I will tell you what they mean.

Hope this helps -
aloha
calvin