I havn't had much time to drive the Disco. But did drive it around today and it used a bunch of gas. Looks like 6mpg. Thats pretty terrible. Everything runs fine and I don't have a CEL or any codes.

My first guess is my O2 sensors. Is there other ideas that would cause such terrible gas millage?

Edit: I should also mention that in a different thread I mentioned how my O2 sensors are show 0.0v from the odb2 reader. The first 3 O2 sensors show 0.0V and the last one shows 1.3v (pic attached)

 

Go on amazon buy 2 new upstream ntk brand, they are cheap there, I am still leaning to an ecm or wiring issue

But if you have not done the o2 probly due

 

I found these on amazon. from the sounds of it these are the ones I should use?

Also has anyone ever pulled o2 sensors and tested them with some heat and a voltmeter/scope to see how good they are working. just curious.

 

Think about your last question. Why would you use heat to "read" your O2's? Yours are toast since they don't respond quickly, they've lived a full life, bury them.

You may have one heck of carbon pancake sitting on your piston crowns while enjoying that 6mpg...... might want to address that little problem. Have you checked wether the PCV is open?

 

Gotta chime in...

With the support of the people on this forums you can accomplish 90% of the work and save yourself some $ and head aches.

1. Buy O2 sensors, replace them all... Get it out of way...

2. Replace air filter

3. Put a full tank of premium in, add half a can of Seafoam to the fuel system.

4. MAF (Master Air Flow) sensor... Buy the aerosol MAF cleaner, YouTube it... Takes 5-10 minutes to do and another 30 minutes to dry

5. Idle Air Control Valve (IACV) needs to be popped out and cleaned. Super easy, about another 10-15 minutes... YouTube and people here are your friends

7. PCV valve, make sure it and the little hose aren't clogged.

Lastly...

Have plenty of beer on hand for afterwards

Just my $0.02

 

Those are the ones I bought

 

Trying to trouble and test to find the issue. So if I could test the O2 sensors that would tell me if I'm having a wiring, ecm, or O2 sensor issue. the O2 sensors don't look that bad, so I'm guessing they have already been replaced at some point.

Yes, PCV is open.

 

Thanks beer is always involved.

I've replaced IACV and cleaned ports (that was a issue I had in a different thread)

Cleaned MAF, replaced air filter, PCV cleaned.

I'd like to get the wiring diagram of the 4 wires on the O2 sensors so I could see if these O2 sensors are working or not. They don't look like they are in bad shape.

Anyone know the which wire is which on the O2 sensors? ground, heater, volt ref, and ground?

 

They are included in the full Rave file.
You can go here:
land rover service factory manual RAVE download land rover resource, service manual, workshop factory manual, download, rave, vehicles including discovery, series, defender, range rover, freelander, LR3, Handbooks, Catalog, Catalogue, Land Rover Inte
Save the zip file from link that looks like this:
Land Rover Rave Service Manual large file warning 590MB
Takes awhile to download, it was longer than 30 minutes on my DSL connection. PDF "rave-lr" is in there and probably all you need. Save/Move on your drive where your other manuals reside. Open up, go to your vehicle type and you should be able to find the manuals you may desire.