I live in the Boston area. Lately my 2003 GLE (auto) has been averaging around 18mpg or maybe less in mixed highway/city driving. I do drive around 80 on the highway, but am sedate driving in the city. Typically I am getting around 240 miles when the gas guage reads 1/8 tank left. The car has about 62,000 miles on it. The spark plugs have not been changed yet. Air filter is new.

I've noticed that in the last month when I start the car, even if it is reasonably warm (50 degrees) outside, I am smelling raw gas from combustion right after the start, until I drive off.

I'm not getting any check engine lights. I have to check the manual to see if there is a cold start valve, and am wondering if it is sticking leaving me with a rich mixture.

I would take the car to a stealership, but do not trust them.
I think my best route might be to get a program for a laptop computer for the car OBD2 interface to I can dynamically see what is going on when the car starts up, warms up and is driving at normal temperature.

Any advice would be welcome.

 

nissan data scan 2 awesome device i had one will let you do all kinds of stuff with the ecu. no abs or bcm stuff but should let you do everything you want and advance your timing 17 degress if your into that stuff. good luck on that also could be your fuel preasure regulator. it has a diafram with a vacum hose on it and pull that line off. the diafram could have a tear and fuel will then leak back into the vaccum line cause way rich/fuel smell. simple thing to check

 

Fishtale, I looked at http://www.nissandatascan.com/
I'm not easily finding where the thing would show O2 sensor data, though I admit I have to do some studying on what OBD2 can show (like if the car is running too rich)
So I guess I have to try to compare some googled generic OBD2 laptop sensor programs to see what kind of data they show vs the nissandatascan

 

Sorry to pull up an old thread, but i am having the same issue and i tried to look up the fuel pressure regulator, and it seems like 02 and 03 does not have it. Maybe i am missing something?

 

tune up ecu relearn spark plugs,check for exhaust leaks and oil pan leaks then check back