You are here:

Land Rover Repair/Trouble 96 Land Rover Discovery


When engine gets hot approx. 7 miles on the highway starts bucking around 70mpg. When cold runs great over 70. Have changed all 4-02 sensors, plugs, wires, fuel filter, camshaft sensor, all oem parts and a used vss sensor. Took to muffler shop and they said both cats check good. They also checked for codes and came up with what I do with my checker P0340 Bank 1 malfunction. Could use your advice. Thanks

This is a situation where fault codes alone don't tell you enough.  If your truck were in the shop at Robison Service what we would do is drive it with the T4 system connected and look at the live data screen.  T4 has a mode where it will highlight any out of spec sensor readings and a drive with that tool would surely reveal what's going on

Without proper testing, you're just guessing and throwing parts at it.  As you've probably discovered, that gets expensive

Could be a mass air meter, a failing coolant sensor, an ignition coil breakdown, a crank sensor or reluctor problem . . . the list is long.

Land Rover Repair

All Answers

Answers by Expert:

Ask Experts


John Elder Robison


I own J E Robison Service in Springfield, MA. We are Bosch Car Service for Land Rover, BMW, Mercedes, and other European lines. I can answer most questions about Land Rover service or repair. I'm known as a car enthusiast, machine aficianado, photographer, writer, and speaker. I've been around Land Rovers and British cars most of my life. Visit me at my car business, or my author website, Check out my autism and writing blog at or my photos on John Elder Robison


I have been a Land Rover service manager since Land Rover returned to North America in 1987. My company is a four-star Bosch Car Service facility, known nationwide for Land Rover service, overhaul, customization, and restoration. In addition to Land Rover our company services BMW, Jaguar, Mercedes-Benz, Rolls_Royce, and Bentley motorcars. We have factory-plus-level service capability for all makes. Visit my company online at > service > land rover Also visit my blog at


In the Land Rover world, my writing can be found in various print magazines and online at robisonservice.blogspot,com. In the wider publishing world, my work is published by 20 publishers in over 50 countries. Mt books Look Me in the Eye, Be Different and Raising Cubby have made US and international bestseller lists.

I am ASE certified, Bosch Trained, and trained by Omnitec/T4 and Autologic on their Land Rover test systems.

©2017 All rights reserved.