Quote:
Originally Posted by berni29
Hi
"The P0134 code is telling you that the DME/ECU is not getting any signal from the sensor.
So the sensor is dead or you have an issue with the wiring from the DME to the sensor.
Most likely a wiring issue.
I would look at the wiring connection at the sensor and the sensor wiring harness."
I agree with the above except that I think it will be the o2 sensor. If it is the wiring I would be interested to know the fault. I have that code and for me it is an ECU problem. There again I did cut all the wires to the o2 sensor at once while the engine was running, so I have shorted something in the ECU out.
Best of luck
Berni
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First lets look at what we are dealing with.
A code: P0134 when you look up that code it states: "pre cat O2 sensor cyl 1-3 signal implausible/open circuit/no signal.
There are three possibilities:
1. Bad ECU
2. Dead sensor
3. An issue with the wiring between the ECU and the sensor.
The car is a 2002 with 62000 miles.
An issue with the ECU is the least likely cause of the problem.
Unless of course the owner shorted it out while cutting some wires or doing other work while the engine was running. as you did in your case.
There could be an issue with the ECU but it doesn't happen often.
The second least likely issue is a dead O2 sensor. The car only has 62000 miles on it.
O2 sensor signals slowdown with age but very very rarely go compleately dead and give no signal.
There is also the matter of the P1128 code which is from the bank 1 pre cat O2 sensor.
This leaves the most likely cause of the P0134 code to be an issue in the wiring between the O2 sensor and the ECU.
Something as simple as a loose connection at the O2 sensor. Or the same at the ECU.
The signal wire could have rubbed and shorted. The ground wire could be loose or corroded.
The AOS was replaced in the past so maybe the O2 sensor wiring was disturbed in the process.
Always go with the simplest things first and work your way up the diagnostic tree step by step.
Some simple tests with a multimeter would tell you if it is the ECU, the sensor, or the wiring.