fault on lambda loom

[steveo]

hi all my car ticks over very crappy so had it pluged in on a tester it came up with a fault saying there was a grounded earth on the lamda sensor so got a new one but problem still there,so i tested all for wires on the main loom and there was 2 earth's there should only be one,does any body no if these four wires go strait back to the ecu because i need to trace them all back to see where it is earthing or if it is the ecu

[ANDYC]

if its got 4 wires to it ,it has 2 earths

[Stu]

A signal ground and a heater ground.. technically the signal ground should go back to the ECU's sensor ground input.. which the loom does

[steveo]

if its got 4 wires to it ,it has 2 earths

thanks both wonder if my lambda sensor has had it then