RangeRovers.net Forum banner

1 - 4 of 4 Posts

·
Registered
2010-2012 Range Rover MkIII / L322
Joined
·
111 Posts
Discussion Starter #1
I have noticed this for a while. But I am now getting an occasional CEL Code P0420 for bank 1 catalyst inefficiency. It’s 2k for a new pair.. and the light sometimes goes out itself. I replaced downstream O2 sensors and problem stayed away. Anyhow, holding steady throttle on a flat surface, the instant MPG reading jumps from 20-24 mpg, every half second. If accurate, seems the fueling is not being consistently delivered. Or a vacuum leak or bad sensor.. every other vehicle I have driven will show a near solid and consistent mpg reading when level and no throttle changes.

Can an anyone else comment on how their instant reading behaves? Would be very helpful in chasing the issue.
 

·
Administrator
Joined
·
27,801 Posts
The info button instant economy read out is a general info bit and should never be considered accurate. It is no way a measurement of fuel delivery. Just as the average can easily read 80+ MPG going down hill with your foot off the throttle or if reset again you can get 2MPG going up hill at full throttle.
 

·
Registered
2010-2012 Range Rover MkIII / L322
Joined
·
111 Posts
Discussion Starter #3
The info button instant economy read out is a general info bit and should never be considered accurate. It is no way a measurement of fuel delivery. Just as the average can easily read 80+ MPG going down hill with your foot off the throttle or if reset again you can get 2MPG going up hill at full throttle.

Clearly. But the data comes from somewhere. The question is not if it’s accurate, it’s if it’s supposed to be constantly bouncing around under Un - changing loads. Gives me reason to believe that sensor readings are bouncing around more than they should.
 

·
Administrator
Joined
·
27,801 Posts
The "trip computer" is a toy, it is a gizmo. You are barking up the wrong tree using the trip computer to diagnose an issue. As far as other cars not fluctuating... different car maker's programs have different buffers on the read outs.

Purchase a diagnostics system and read your live data. That is the only way to see what is really going on in real time. There's the diagnostic equipment forum below with plenty of information on available systems.
 
1 - 4 of 4 Posts
Top