I have my 2004 Land Rover Discovery SE 2 (4.6) in the shop for about 5 weeks now, my mechanic can not seem to figure out why it runs rich on fuel? what could he be missing? anyone know?? These are the codes that keep coming up, even though he replaced parts with good, new parts. (spark plugs, wires, coil,& plerum gasket, v/c gaskets, both sides, swap MAF sensor, checked ox sensors, all vac connections have been replaced) Has a rough Idle.
Codes:
P0414
p1884
P1482
p0102
p0340
p0448
p0445

 

Most of us do not memorize the code numbers meanings, suggest you post the RAVE explanation for each if you want assistance troubleshooting.

 

I agree with Extinct. Make it easy for people to help you.

But I was board so I did a 10 second lookup on them. All over the place. SAI,coolant temp, maf voltage, cam position, evap codes. And as best I can tell 1884 is a CAN error that can mean a laundry list of other things.

I would start thinking bad ground somewhere. About the only thing I can think that all these systems have in common is electricity. An intermittent or weak ground would cause all the signalling to be erratic.

 

Look at weak battery and charging system too. You can also consider clearing all codes and starting fresh, taking new codes as they come. The worst offenders will come back quickest. With a noticeable rough idle you will get the most important codes immediately.

But, don't spend any time troubleshooting anything until you check out the electrical. If that is bad, nothing else matters. Bad electrical can be the direct cause of your problems, and it could create codes for things that aren't actually bad.

 

I noticed that there is black residue on the driveway below the exhaust pipe and a thick coating ring on the exhaust pipe of black. My mechanic did clear the codes and every time he starts it, the codes comes right back. When you say electrical issue, do you mean the computer itself, or a connection someplace? The battery is new.

 

What we mean is those codes don't appear on the face of it to really be related. Evap, coolant temp, cam position, etc. What they all do have in common is they require a steady voltage and resistance to provide the computer with data in the expected ranges.

Most likely a connection, but one that all these components share, which would be a ground somewhere. A bad ground could also result in weak spark which might appear as running rich/incomplete combustion.

Start with the battery. New≠Good these days unfortunately. 12.5 ish volts no load, above 9.6 volts when cranking. Inspect the battery cables, our vehicles are old enough corrosion hides in the terminals and under the insulation. Follow both leads and check the connections on the other end, and finally check both ends of all the engine and body grounds. I would have to consult RAVE to know all the places there primary grounds. It's gonna take an hour or two, but it is time well spent.

 

I can tell you how to troubleshoot each, but will need the code description to do so.