mpg drop
#41
#44
For example, if a fuel injector is leaking-- it will set a misfire code initially, and the O2 sensor immediately responds saying the mixture is rich. The computer will lean the mixture on all cylinders to compensate. This usually exacerbates the problem, as none of the cylinders are at the proper mixture-- the leaking one is still rich, and the others are lean. The ECU still cannot straighten things out, and since the MAF, CTS, AIT and other sensors are reading appropriately, it disregards the O2 sensor and gives you that code, even though it's reading rich like it's supposed to (for the theoretical leaking injector).
Just giving you an example of why codes can be misleading. If you replace it and it's still bad, start troubleshooting elsewhere.
#45
I still have my little magic decoder code ring running.
http://enginecodemaster.com
Has lots of the rave codes in it.
That site is running on a Rasberry PI that a college intern gave me as a present.
I got 16 MPG on mixed highway and city. If and only if I used premium gas and
I drove the rover never over 55 MPH and I drove it like there was an egg on the gas pedal.
But I was pretty surprised I could get that MPG from a big square lumbering Discovery.
Just drive it like a prius. You'll probably get more MPG.
http://enginecodemaster.com
Has lots of the rave codes in it.
That site is running on a Rasberry PI that a college intern gave me as a present.
I got 16 MPG on mixed highway and city. If and only if I used premium gas and
I drove the rover never over 55 MPH and I drove it like there was an egg on the gas pedal.
But I was pretty surprised I could get that MPG from a big square lumbering Discovery.
Just drive it like a prius. You'll probably get more MPG.
#47
#48
Yeah yeah yeah..
Well.
You don't feel the large heat buildup...
There is a REASON!!!!
OK well when your O2 sensors were bad..
The ECU switched to the FUEL MAP
and the FUEL map is static.
It tends to OVERFUEL.
The excess fuel is not burned.
Goes out the exhaust.
Into your cat convertors.
Those
go supernova to burn the excess fuel.
And that ruins your cats.
Melts all the rubber near them too..
And give YOU hot feet.
Well I am REALLY GLAD to hear you got the O2 sensors in
and your cat convertors are not two small Suns or stars glowing white hot.
You are now in the "closed loop club".
A closed loop means the O2 sensors are feeding back to the ECU.
ECU controls the fuel injectors.
Fuel injectors set the mixture.
Mixture affects the Oxygen that the O2 sensors sense
and feeds back to the ECU.
Good job!
Well.
You don't feel the large heat buildup...
There is a REASON!!!!
OK well when your O2 sensors were bad..
The ECU switched to the FUEL MAP
and the FUEL map is static.
It tends to OVERFUEL.
The excess fuel is not burned.
Goes out the exhaust.
Into your cat convertors.
Those
go supernova to burn the excess fuel.
And that ruins your cats.
Melts all the rubber near them too..
And give YOU hot feet.
Well I am REALLY GLAD to hear you got the O2 sensors in
and your cat convertors are not two small Suns or stars glowing white hot.
You are now in the "closed loop club".
A closed loop means the O2 sensors are feeding back to the ECU.
ECU controls the fuel injectors.
Fuel injectors set the mixture.
Mixture affects the Oxygen that the O2 sensors sense
and feeds back to the ECU.
Good job!
#49
#50
What scan tool are you using for reading codes and the O2 output? Can you post fuel trim? Would be helpful to know what the long & short term fuel trim are doing at idle, part throttle (cruising) and moderate throttle.
Don't just throw parts at it unless you like wasting money. I wouldn't point fingers at ignition components unless I knew fuel pressure & trims were good, or I had a reason to suspect it (old or high mile wires & plugs).