O3 Maxima_ Plugs_ECU_Mileage

[revo747]

I have changed my plugs which was quite a experience getting to the rear 3 plugs but found a nice thread to help out. The old plugs were so worn, i couldnt believe the car was running so well or even running at all,( there gaps were huge with the center prong burned way down). I expected to start getting alot better gas mileage after replacing these but actually think Im getting less. Im averaging about 21mpg with alot of highway driving, thought i should be getting alot better.
question?
Do I need to reset the ECM after changing the plugs?
Do I need to have the timing adjusted? if so, where do you advance and retard
What mileage should i be getting?
Any suggestions on how to improve MPG?

Thank you,

[robo_geek]

Originally Posted by revo747

I have changed my plugs which was quite a experience getting to the rear 3 plugs but found a nice thread to help out. The old plugs were so worn, i couldnt believe the car was running so well or even running at all,( there gaps were huge with the center prong burned way down). I expected to start getting alot better gas mileage after replacing these but actually think Im getting less. Im averaging about 21mpg with alot of highway driving, thought i should be getting alot better.
question?
Do I need to reset the ECM after changing the plugs?
Do I need to have the timing adjusted? if so, where do you advance and retard
What mileage should i be getting?
Any suggestions on how to improve MPG?

Thank you,

In general, 3.5L maximas tend to get around 20mpg. It's around 24 or 25 on the highway, and about 17 city....average around 20. I get around 20mpg in my 2007 in mostly freeway/rush hour traffic.

Link to fuel economy ratings of 2003 Maxima:
Gas Mileage of 2003 Nissan Maxima

To answer your questions:

You don't need to reset the ECM or adjust the timing; the computer takes care of all that.

There are no silver-bullets that are going to make your MPG go waaay up. The general things like limiting the use of the A/C and keeping tires inflated properly are probably the best advice I can give.

[sergey85]

its not a bad idea to unplug the battery for a few hours to reset the ecu, make sure your air filter is clean