O2 (Lambda) sensor problems solved!

[JohnandSteve]

Since there's nothing so annoying as people getting help from a forum and then not posting the solution, this is what solved it.....
Firstly, the symptoms: P0134 and P0135 - sensor 1 'no activity detected' and heater problem
P0141 Heater problem on sensor 2
General lack of power and then, when we changed sensor 1, lots of misfiring and 'surging'.
What's not got to be forgotten under these circumstances is that you can disconnect both sensors and the engine will run fine on it's default settings. A good interim solution.
So what was the solution?
The problem turned out to be a poor earth and this was corrected by fitting additional wires to the grey wires coming off the sensors. These were then terminated in a ring connector and fixed under a bracket on the engine. We did both sensors at once - linking both greys and then taking these to earth.
Also, the plug/socket connections were very intermittent so we cut these off and made nice soldered connections with heat-shrink sleeving. Job done.
Hope this is helpful
Cheers

[Huskyxantia]

Excellent