P0138 Code - Oxygen sesor

[Brian425]

I get an occasional check engine light on my 99 D1. I pulled the code and the only code is P0138. The question now is which O2 sensor is bad. At $100 each, I do not want to replace them all. Any advice would be appreciated.

Thanks,
Brian

 

[javelinadave]

Why don't you replace one. If it solves your problem, great. If not, swap out the known new one with the other older one. Hard to believe I use to be a detective.

 

[DiscoDuck]

I pulled the code and the only code is P0138. The question now is which O2 sensor is bad.

P0138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)

I would start by trying the drivers side after the cat.

Shawn

 

[Brian425]

Thanks Shawn. I just found it on another site with code explanations. If it is any help to others, the site is Land Rover Codes

 

[andrewv]

Chis from St. Louis' fingers hurt

Those codes don't positively mean that the 02's are bad. They are simply reading that the input (before the cat) and output (after the cat) are reading something out of the ordinary in terms of output. What they measure determines whether the ECU richens or leans the engine. You may have a vacuum leak or any number of other issues. A code points to the symptom, not necessarily the cause.

 

[Brian425]

Andrew, you have a good point. I did take a look around before I borrowed the code reader. I started with the simple and tried to see if I saw anything. I think that the truck does not like to sit for a week or 10 days at a time. Once I start to drive the truck for a few days, the code goes away and it only comes back after sitting a few days.

I'll take another look around and see if I find anything. It never hurts to check.

Thanks,

B

 

[rdoane]

carbon can sometimes build up on the sensor, go get some fuel cleaner and run it through, fixed my o2 sensor and helluva alot cheaper than a new one

 

[andrewv]

I agree with the sitting around for a week theory. I've always been a big believer that Rovers don't sit very well. I'm faced with the prospect of putting mine into storage except for taking it out on trails, and I think it will probably fall apart from not being driven. Good luck on the fix.

 

[Chris-St Louis]

Those codes don't positively mean that the 02's are bad. They are simply reading that the input (before the cat) and output (after the cat) are reading something out of the ordinary in terms of output. What they measure determines whether the ECU richens or leans the engine. You may have a vacuum leak or any number of other issues. A code points to the symptom, not necessarily the cause.

Couldn't have said it better myself.