Greetings all. I just spent the last 3 years rebuilding my engine from the ground up. (caveat, I also bought a house, got married, started a new career, etc. so yeah, 3 years) She started up nicely after a few dry starts to build oil pressure; runs smooth and quiet, almost too quiet! I couldn't believe my luck that I'd done everything right, but...

I pulled the Landy out of the garage to seat the rings, burp her, and run my Ultra Gauge (UG) diagnostics. Oh, where do I begin?! Honestly, I'm a bit overwhelmed at where to begin here. The only thing that seems absolutely obvious to me is that I need all new O2 sensors, but after that, I'm not sure if its all the problems or just a few problems that will solve most codes. Trying not to replace more parts than I have to. The MIL is illuminated and I get flashing M&S lights after revving to 2.5K RPMs. Getting the following along with notes from RAVE and some thoughts of my own:

2001 Land Rover Discovery 2 SE W/SEC Air

TROUBLE CODES
P0340-Camshaft position sensor circuit malfunction / Open/short circuit to vehicle supply or earth

P0154-O2 sensor circuit no activity detected (bank 2, sensor 1)/ Front sensor RH bank open circuit (REPLACE)

P0135- O2 sensor heater circuit malfunction (bank 1, sensor 1) / Front sensor heater LH bank - short/open circuit (REPLACE)

P0155- O2 sensor heater circuit malfunction (bank 2, sensor 1) / Front sensor heater RH bank - short/open circuit (REPLACE)

P1884 (18)* CAN message: Throttle position invalid / Substitute throttle angle of 50% adopted. No kickdown. Operates in economy modes only.

P1884 (35)* CAN message: Engine speed invalid / Maintains current gear in low range, limp home mode in high range. Shift pressure to maximum, harsh gear shifts/engagement.

PENDING TCs

P0102- Mass or volume air flow low input / MAF signal < minimum threshold, which is speed dependent (Cleaned MAF with MAF aerosol cleaner and electrical connector with Elec. conn. aerosol cleaner)

P1451-Possibly Purge Valve or Fuel Leak Detection Pump (Replace?)

P0414-SAI vacuum solenoid valve short circuit to ground

P0445-Purge valve short circuit to ground

P0448-CVS valve short circuit to ground

P0134-O2 sensor circuit no activity detected (bank 1, sensor 1)/ Front sensor LH bank open circuit (OK, I get it. ALL NEW O2 SENSORS)

P0123-TPS a circuit high input/ Signal > maximum threshold


THANKS ALL!

 

After siting for so long, l'd be looking for chewed up wires. You've got all sorts of codes, one from every direction. Check down by the ECM, follow harness through firewall and out into engine compartment, examining as you go.

Also, has the ignition ever been turned on, while the engine was out and harness/sensor plugs all disconnected? If so, a bunch of these codes could have been "set" then. Since you have a record of them, clear the codes and see what ones come back...then go from there. If they all come back, then check harness as mentioned previous. But, l'm thinking the key's been turned on while connections were not plugged in...and these codes all set then.

 

Great advice above. The only thing I'll add is something obvious. Since you're presumably just reattached your Y-pipe, it will save a ton of time to drop it again to change out all your O2 sensors.

 

I did have a few critters camping out. I'll take a look and see if they chewed up anything and get back. I cleared all codes after starting it up. These are fresh codes. Thanks for the help!

 

M&S light is linked in lots of cases to a failing battery. Good idea to have the local auto parts store perform a stress test, it may save you a lot of time.

 

It's a brand new battery and I tested it myself. Battery @ 12.87V with the engine off and 14.38V while running. I think maybe the terminals need to be replaced. I ordered new ground lead and a kit to replace the connection for the hot side. I'll report back to see if this fixes the MS flashing Disco party. Any other thoughts? Thanks for the help

 

I assume you mean the catalytic converters? I think I'd rather keep my new exhaust manifold gaskets compressed, as I don't have any leaks at present. The O2 sensors don't seem that difficult to get to if you've got a proper tool. But that's not a bad idea if it really is difficult to get at them. Thanks!

 

Well, you don't have to remove the manifolds so it's only the outlet gasket but that's up to you. I removed my y-pipe to replace O2 sensors which seemingly hadn't been out in forever and were near impossible to get out in situ, correct tool or not, and the whole job was under an hour. After which the outlet gaskets were reused without issue. I did not yet have to deal with the cross brace under the y-pipe however because it was still off the truck at that point so if those bolts are frozen that you'll have to deal with the O2 sensors in the conventional manner, or suffer through that hell as well.

 

O2 sensor aren't bad but the driver upstream electrical connector I find to be a major PITA but not sure pulling the exhaust would be worth the headache.

 

I agree, reads like a wiring problem. Clear the codes. Get an elm327 and the torque app, chart the oxygen sensors and the MAF sensor, tps. You can check the TPS with the engine off even.