I finally got around to replacing the passenger side manifold. The old manifold had a crack that went half way around the tube. And the LR was being driven around with that crack in the manifold for about a year. Not as a DD.

Test drove the LR and everything seems fine.
I erased the codes. The SES light is off.
I checked the codes again and it brought up two codes

P0135 - sensor heater
P0134 - Sensor CKT no activity

I have changed the two front O2 sensors about a year ago.

What I need help with is finding what these codes actually mean and other issues I should be looking at. Any help would be great.
Thank you.

 

IMHO the system is trying to tell you that wiring to O2 sensor(s) is disturbed. It believes the O2 heater circuit is not allowing sensor to be heated up, and as a result, the output signal voltage is not changing, but is above the limit to show up as a short circuit.

May want to check connector for sensor.

2 pages attached from the Bosch engine management manual for your review.

 

Bank 1 sensor 1 needs to be replaced, no big deal. Have you ever replaced all 4 at the same time to help maintain your performance by balancing your air fuel ratio between both banks?

 

Thank you both for the replies. I have not replaced all four sensors at the same time.

About two years ago I changed out both front sensors. Took it to the dealership a year ago and they told me they had to replace the front right sensor. So basically the front right sensor has been changed out acouple of times in the past.

Looking through the service records (both mine and the service mechanics) I dont see the rear sensors ever being replaced. Ill have to get on that one. I hope they dont cost as much as the front sensors do. I paid $187 for each of the front sensors at the dealership.

 

check Amazon.com for the o2 sensors

 

What brand of O2 sensors is recommended if youre not going to put in the Genuine Land Rover O2 sensors?

 

I replaced my front two (the front control the air/fuel mixture and the rear just tell whether the converter is working)a few years ago (no codes, but at 100k miles, I figured they could use replacing) with Bosch sensors and have had no problems whatsoever.

 

Sounds good. Thanks for the replies. Ive ordered some Bosch replacements and they are enroute, be here in a couple of days.