A clogged cat is a possibility PA, but i doubt its bad... to actually diagnose a cat failure involves removing it and see how the engine behaves then.

 

The air filter was replaced a month ago when I had the oil change done. as for the spark plugs, they have not been replaced in past 3 years that I have had the car, but if one of the plugs fails, will the engine work at all? The way engine is running, it does not feel as if is is misfiring, it just struggles to accelerate. The fuel filter has not been replaced either, in the past 3 years unless Nissan dealership replace it when they replaced the fuel pump (pardon my ignorance). Is there any easy way to determine if there is a problem with the transmission itself, like by shifting to D2 while driving uphill or something?

 

If rpm increases significantly w/o acceleration or increase in speed, the transmission has a problem. From your description, the transmission is slipping badly.

good luck

 

The plugs could be worn out and not giving you a strong spark.

Here is a link for the owners manual: http://www.nissanextendedwarranty.co...r_manuals.html

It says to replace them 30k/2yrs, so you are past due. This is something that needs to be done and is a cheap fix compared to having the tranny diagnosed.

 

YES. After re-reading the original post, I gotta agree with this.

Bad plugs or a plugged cat would cause the engine to lose power. In that case it WOULD NOT rev high. Revving high indicates the engine is making the power, but the tranny cant deliver it to the axles.

With a manual tranny, that means you simply need a new clutch. With an automatic, ???
If it was a 98-02Honda automatic, the trannywould be near-death.

 

I am changing the spark plugs this weekend, and will post the results. Is it necessary to change the wires as well?
Also, another thing that I forgot to mention was that the car gives terrible mileage, approx. 18 MPH or less within city. Is it associated with the OBD II code P0240: Catalyst System Efficiency Below Threshold (Bank 1)?
Thanks

 

Slipping isn't the 6th gen design flaw. Slipping means the frictions are shot. Still means that the tranny needs to be torn down or replaced, but friction replacement is cheaper than buying a new tranny in most cases. L10 and Dr. Evil can upgrade the tranny at the same time to lessen the chance of true tranny death, but at a price.