I have been experiencing a reoccurring problem with my 2003 Auto SE. After doing an ECU reset I notice that my power and gas mileage noticeably improve. After I drive for a few hundred miles I notice a loss of the low-end snap, I am also lucky if I get 300 miles per tank. Once I reset the ECU the power and mileage come back again. Even when the car is running at its best, it is still noticeably slower than the girlfriends 02 Auto Altima SE (the dealer tells me that the Ulti’s are quicker).

I realize that my ECU is probably adjusting for something, causing it to decrease the timing, decreasing performance. Do any of you have any ideas what it could be? I am wondering if it is the knock sensor (I have not noticed knocking) I am not flashing any codes. I have tried gas from all over with the same results. I always use at least 93 octane.

 

Did you have the CAS (crank angle sensor)done to your car yet? If not i bet that is the cause of your loss of power and milage.There is a TSB out for our 2k2,2k3 Maximas. Unfortunately you have to have the campainge letter sent to you and in hand in order to have the dealer to do the work for you for free. If you haven't gotton your letter go to your dealer and buy a oil filter and let them take your info down , usually within a few weeks you will get a letter directly from Nissan of America, saying, blah, blah blah, get this CAS done imediately. Go to your local dealer and they can look up your car serial number in there computer to see if you have had it done. If so great, then its something else causing your problem, if not, i bet you 99% that the CAS is your cause.

Hope everything goes well!

 

Thank you,
I have had the recall taken care of already. Do you think there is a possibility it was done incorrectly?

 

Its possible but i doubt it.....
Does the SES light come on? If it doesn't, you can have the dealer do a diagnostics on your car to make sure everything is working well.
How many miles do you have on the car? Is your air filter dirty? Plugs bad?
You know some people have had bad coil pack which caused problems. Although i don't think its a bad coil, because a bad coil would cause your car to buck,sputter , etc.

I say have the dealer check it out again, i know i would do that first.

 

My SES light is not coming on. I have a new airfilter with ~1000 miles on it (still very clean). THe car has 23K on it. If I reset the ECU I get the power back for a short time. I think the ECU is adjusting for something.

 

Durckelg: the problem is not with the crank sensor recall, but with the TSB NTB03-023. That is the lack of power TSB. Id suggest having that done, as well as an induction cleaning service. Another thing I noticed whilst having that problem was that after i changed the exhaust, I looked at the cat and noticed it was totally clogged. Id check all that stuff first. If you need more info, PM me.

 

Thank you,
I have already been to the dealer with TSB in hand. They keep feeding me BS about not being able to do anything unless they can pull a code. I will try a different dealer.

 

Try a different dealer and ask them if they can do a TSB for you with an oil change (if its not time for a change, then wait till it is). Some dealers dont want to do anythign cause they wont make $$$. If you have a svc claim, they will be more likely to "throw it in"