I have a 2003 SC. Today it has died 85 times when coming to stops. It wont accelerate fast, and creeps through the intersections before the power kick ups. The RPM's are going to 4.5 before it feels like it shifts (automatic) and while I was going 60mph it felt jolty. I need help. This all started today when it was warm and cold.Also, When going up a hill (on my dirt road) it felt like it was going to die and hardly had any power. As a side note, I have only used Premium gas.Fuel filter was replaced less than a year ago and it DOES have gasoline. Any ideas? It started this morning and I thought I was going to get killed all day! And when it dies, it sounds like a garbage disposal under the hood? Also, the check engine light is not on, unless it dies-then it is on.....

First off I would try to get the codes read. Now, although I have never heard anyone give the symptoms of a KS (Knock Sensor) problem, I am going to guess by the sounds of it that you might have a KS code in there. Seeing as you have the SC model, the KS code does matter to you, unlike the Non SC models. If you have a KS problem odd's are you're X may be in limp mode.

Until someone who knows more about it chimes in, try reading up on KS issues. and maybe include your current mileage, and any work that has been done recently. ie; timing belt kit replaced by 105k miles etc etc....

Thanks so much for the reply. I have about 130,000 miles on it. I got the timing belt/water pump/spark plugs in December. Just had exhaust leak fixed 2 weeks ago. I want to get the codes read, however I was told if the check engine light is not on, there will be no codes to read? Does that sound accurate? Thanks for your help, I figure once I get on lead on what it could be, I can start working on it...I have been told about 30 different possibilities.
Thanks again,
April

yes, you can have codes without having a Check Engine Light on. Its usually the more serious codes that will turn the light on. Since replacing my engine I've gotten codes for the KS several times, "P0328" (Knock Sensor 1 Circut High Input (Bank 1)) that did not turn on the CEL, but did not have any issues with how it ran with that code.

I have had the CEL turn on for "P0430" (Catalyst System Efficiency Below Threshold (Bank 2) ). again , guessing this was a more important issue since it turned the CEL on, but did not affect how it ran at all. I've done a SeaFoam treatment and havent had the last code come back since.

If you do get the codes read, make sure you write down what they are and search them on the web to get an idea whats going on, or bring it back here and ask, lots of info for it out there.

it's not a knock sensor issue..........

I agree, it's not the knock sensor. Sounds like a spark issue. You said the plugs where just replaced, but it could be they're the wrong gap? or cap and rotor? wires?

I'd start there.

So I broke down and took it to a mechanic who ran the codes and they were both the Knock Sensor and the Catalyst System Efficiency.Weird. He thought it was the Mass Air Flow sensor or the wires. He charged me 85$ to tell me to bring it back Monday to run all new wires for the MAF.(when putting pressure on the wires that go into the MAF the engine would die) I went and bought a new MAF and since then it has not died (woo hoo), but is running kind of jolty/stuttery-not while stopping, just while driving. Any ideas if wiring could do that?
Also, the sparks were done in December, do you think that the problems could start now from a wrong gap, etc.?
Thanks everyone from your input! Hey I was reading in another thread that someone said that unless you a SC the knock sensor code was okay, I DO have a SC though and I am getting that code. Is there cause for concern? I was quoted around 800+ to fix that...Me No Likey!
April

Just went through this for two months with my '02. It was very intermittent for a long time. Tried the MAF, Throttle body sensor,fuel pump, fuel filter and sending unit, distributor cap and rotor. Nissan was just reading codes and guessing. Started working with a local shop that traced it to my distributor itself. Replaced the whole thing. So far it hasn't been back.