Check engine warning light on?

The service engine soon lit. It is the first time. The fuel cap is ok, and tighten. It stays lit.I am a bit worried. What else can it be. Thanks in advance!

Similar to lrmorrison, I too experienced difficulty accelerating while on the expressway about 3 months ago and then again this morning. Took the vehicle to the dealership the first time. They did diagnostic testing but found nothing. On the way home from work today, the problem occurred again with the 'service engine soon' light coming on. I was able to drive home traveling less than 40 mph and plan on taking the vehicle to the dealership Monday morning. Now that the service vehicle light has come on, their diagnostic tests will hopefully be able to determine the source of the problem. It's quite scary not being able to accelerate with your vehicle already in motion.

Thank you very much for that suggestion!

I used to have the same problem with my GMC Yukon. Seemed to only happen when the engine was warm. I happened to mention the problem to a tire technician after he had trouble accelerating my vehicle into the garage to install new tires. He asked if I used a K and N Air Filter and I said yes. He said that unless they're cleaned regularly (mine was not) they cause more harm than good. My husband used q-tips and a spray-on cleaner made especially for cleaning Mass Air Flow sensors. (You have to take it apart and clean the wires and filters.) As soon as he cleaned it, my sporadic accleration problems that no one had previously been able to diagnose correctly, were solved!

Hi, i've got a 2004 pathfinder chinook(canadian edition) with only 45000 km. Since owning it for a few weeks the service engine soon light has been on. It was on when I bought it and my manual said, 1- could be unsecure gas cap.( It's not ) 2- low gas and to fill up tank and after a few? Trips it should disappear if not get it serviced. (When I bought it, it was on empty, I filled her up and still on.)How many is few trips? I only did 245 km with it thus far. Could it also be something else? Thank you for reading.

My check engine light comes on when using shell gasoline. What could be the reason for this.

Check Engine light keeps coming on. Then after a month goes off for a coule of weeks then back on.I had new cats put on both sides by the dealer and light was off for a couple of months and now it is back on. Any ideas?

I recently replaced all 4 o2 sensors along with the # 1 coil and 4 spark plugs. The following day the check engine light came back on! What could be going wrong this time?

It could be one of your catalytic converters. I have an '01 and have had the same endless problems with ignition coils, 02 sensors, and cat converters.

I had one of the cat converters replaced while it was under the emissions warranty, but I think you're out of luck based on your mileage.

I'm not positive, but I think replacing one will run up near a grand.

2001 Nissan Pathfinder with "Service Engine" code of 1320?

Is replacement of ignition coils something that my son and I could attempt, or do you recommend the expertise (and tools) of an experienced mechanic? I have a very good auto workshop whose quality of repair I always trust. And what might I expect as to cost?