So, I bought a '03 Disco II from original owner with 93k and all service records. It allegedly had blown or leaking head gasket. I don't believe it did but that's a different story. I ripped the engine apart down to the block and after about 6months, I put it all back together new gaskets headbolts and fired it up. Runs awesome, drives great no out of the ordinary leaks, no overheating. POP! code P0130 bank 1 sensor 1. great, i live in georgia and need to pass inspection. checked sensor, looked original and horrible. In addition on live data scan it was showing zeros. Ordered black box bosch off Amazon 15175. Installed today, fired it up, all 4 sensors showing running values. Beer time! POP! new code P1129 front sensors transposed...how the hell is that remotely possible. Beer time cancelled. Checked live data values and bank 2 sensor 1 is showing zeros and is a newish sensor that was working just fine prior to replacing it's brother. As an engineer, this vehicles computer is blowing my mind. I'm wondering if the 1/4 tank of gas that sat in it 6 months had anything to do with this. I'm going to disconnect the battery. No codes were present or pending when I bought and drove it an hour home. The code popped up as soon as I started it and put it back together. I have less than 30days to complete a drive cycle emissions testing and now it looks like i'm chasing codes. I have read a lot of postings from the past 7 years and quite honestly they are all over the place.

 

How many miles you drove since? I'll just re install the O2's and drive it. Let the system, reset itself. Once you reach 80 to 100 miles over, check the codes. Just write all the codes history for the time being.

 

Maybe 30miles. I just snuck it on the freeway for a bit and monitored the sensors live. It stored P0150 which that one was showing values now after I disconnected the fuse and battery to check them but the values are really low. Also, P0174 for system too lean bank 2 is pending.

Maybe be I just need to temp tag this and drive it for awhile and see if it will sort itself out like you said. Man does this engine throw off ridiculous heat!

 

A great many people here have had problems with Bosch O2's from amazon. I had multiple returns. Had a long talk with the guys at AB. These are what UK dealers put in as replacements:
Land Rover Oxygen Sensor Replacement (Same Fit As Part # 250-24496)
Put them in mine, work great.

 

I'm getting a temp tag now so I can put some miles on this thing! If I have to order another one, I will probably get the one from AB. The ECU can't seem to make up its mind so I'm going to try and complete the drive cycle and go from there.

 

One other thing you need to do is really clean the sockets prior to connection. If you have leaky valve covers oil can seep in. Last thing is to really, really, really ( can't say this enough) is make sure the connections are full locked together.

 

Ok, so I reset some codes again and took it on a trip yesterday to get all my drive cycle I/M tests done. Success all were ok and only a couple codes pending which was fine. it passed emissions flying colors today. I'm thinking now that I probably did not need to replace that sensor and let the system run through its fault code findings, clear codes, run it again and the system would have recognized everything perfectly like it ended up doing. I have a feeling, many a owners have replaced everything under the sun emissions wise trying to circumvent ECU. If I had not of done it the way I did, I probably would have had to put about 300 miles on it easy. Well, at least it has another new sensor in it and awhile before I have to go through this again. AND THEN, the garage door beam and unit fell on my rover...but at least I have tags and beer now. oh well lol!

 

Great! its all about the cycle and tons of luck. True some codes that are pending usually wont trigger the SES light. Cheers!