[Mk2] [Generic] Ongoing fault 21 that won't go away? Need someone's help

[chaos19810]

Hello

I've been trying to trace an ongoing fault on my rev5 tubby conversion (used a rev 3 engine) that I can't seem to solve, I have a problem with the ecu recording a fault 21 which I know is the O2 sensor. So far I have replaced the lambda sensor twice, I've also rewired a new plug into the loom, as mine was Bodged with a connector block. None of these solved the problem.

I then checked the wiring using the bgb guide and following the flow diagram and it came back as normal. I then did a individual continuity test on all wires and they all checked out and none seem to broken as I expected. Then finally as a last resort I changed the ecu and still no joy I have a fault 21 before i even turn the engine over.

What I have noticed is that it starts to flash as if all is ok, and then it goes on to the fault code?

Does anyone have any ideas

[bobhatton]

Hello

I've been trying to trace an ongoing fault on my rev5 tubby conversion (used a rev 3 engine) that I can't seem to solve, I have a problem with the ecu recording a fault 21 which I know is the O2 sensor. So far I have replaced the lambda sensor twice, I've also rewired a new plug into the loom, as mine was Bodged with a connector block. None of these solved the problem.

I then checked the wiring using the bgb guide and following the flow diagram and it came back as normal. I then did a individual continuity test on all wires and they all checked out and none seem to broken as I expected. Then finally as a last resort I changed the ecu and still no joy I have a fault 21 before i even turn the engine over.

What I have noticed is that it starts to flash as if all is ok, and then it goes on to the fault code?

Does anyone have any ideasImage Replaced With URL For Quote

So you have a new 4 wire Toyota O2 sensor fitted?