O2 sensor madness
 

I am at my wits end. I have replaced my o2 sensors 3 times within the last 4 months.

I have a 2003 D2 with 112K miles. It changed the plugs, wires, and Mass Airflow Sensor 6K miles (9 months) ago.

It seems like I have been getting about every code related to my 02 sensors. I currently have P0132 and P0135 showing up. I just put in 2 new DriveWire O2 Sensors and my obII reader is now showing that my S1B1 & S2B1 are both stuck at 1.125 volts. The last set I had in were Bosch and gave no readings.

I have pulled the F2 fuse in the engine fuse box and it’s good. I pulled the C0635 connector at the ECM and there’s no corrosion. I sprayed down both connectors with connector cleaner before installing and applied di grease in the plugs. I have sprayed down the exhaust system with soapy water while blowing air in the tailpipe looking for exhaust leaks, and I sprayed around the vacuum hoses with carb cleaner looking for a vacuum leak.

I have run out of ideas. HELP PLEASE!!!

I am about to do O2 sensors. I have read about certain brands causing issues. I went with NTK as I think the consensus was to use those brands. Conversely, Bosch seems to be the only brand for the MAF.

Do you have an Ultragauge so you can take the readings from the O2 sensors and see what they are putting out?

Looks like your codes are both on one back, swap them left to right and see if it follows the sensors.

You almost never need to replace the downstream sensors
NGK and Bosch are first rate - do not get Walker they often fail fast

I fought a similar problem. Turned out that the connector on the harness side had corrosion on the terminal where its crimped to the wire. I got a new connector pigtail from a donor truck.

I bought Walkers when I rebuilt my engine and they both failed within 6 months. Replaced them both with Bosch and they have been fine for about a year so far. These Land Rovers are picky about electronics brands.

Bosch are known to be problematic if you read older threads. NTK (NGK is the parent company, not the brand) is the way to go. I'd ditch the no-name DriveWires, return them if you can.

I’m not familiar with that brand. Do you happen to know that part number I need to get off of the top of your head?

I’m not familiar with that brand. Do you happen to know that part number I need to get off of the top of your head?

Did you have to take your engine down to the block to get enough room to do that with your driver side connector? It’s not the first time I’ve done that, but I would love to not spend my weekend re-building it!

The passenger side should be easy enough though.