New bosch front o2 high readings 1.28v
Discussion
Hey,
So, i bought this car audi a3 8l 1.6 75kw with not working front o2 sensor. I changed it too bosch which was recommended and it's idling on 1.28v. When i press the gas pedal it jumps to something like 0.70v and then goes back to 1.28v. I have tried looking for leaks, but found nothing. Any tips ? And the same time, my rear o2 heater failed, bought used, but working one and still the same code p0141 keeps popping out even though it should't. It feel like the wiring is bad somewhere.. Help :/
So, i bought this car audi a3 8l 1.6 75kw with not working front o2 sensor. I changed it too bosch which was recommended and it's idling on 1.28v. When i press the gas pedal it jumps to something like 0.70v and then goes back to 1.28v. I have tried looking for leaks, but found nothing. Any tips ? And the same time, my rear o2 heater failed, bought used, but working one and still the same code p0141 keeps popping out even though it should't. It feel like the wiring is bad somewhere.. Help :/
How many wires does the upstream sensor have 3 or more.
If more than 3 its a broad band sensor, voltage is irrelevant.
If its a 3 wire sensor then 1.28 is very lean.
Lean mixture could be..........................
Low fuel pressure
Air leak - N80 carbon can solonoid, or oil breather system most likely on that engine.
The p0141 means the heater element in the down stream probe isnt working correcty. This is either your 2nd hand sensor is no good, or there is a wiring issue to the sensor.
Do you have good voltage in that part of the circuit they are fused somewhere in the engine bay, without vin nuber I cant look up which fuse.
Given the down stream sensor effect the mixture I would fix that fault first and see if that fixes the mixture before looking for other reasons for lean mixture.
Hope this makes scense.
If more than 3 its a broad band sensor, voltage is irrelevant.
If its a 3 wire sensor then 1.28 is very lean.
Lean mixture could be..........................
- Fault down stream sensor, or wiring to it.*
Low fuel pressure
Air leak - N80 carbon can solonoid, or oil breather system most likely on that engine.
The p0141 means the heater element in the down stream probe isnt working correcty. This is either your 2nd hand sensor is no good, or there is a wiring issue to the sensor.
Do you have good voltage in that part of the circuit they are fused somewhere in the engine bay, without vin nuber I cant look up which fuse.
Given the down stream sensor effect the mixture I would fix that fault first and see if that fixes the mixture before looking for other reasons for lean mixture.
Hope this makes scense.
Hey, thanks for replying.
The upstream one has 5 wires. After a lot of reading I understood that voltage suppose to be jumping around 0.1 - 0.9 voltage to constantly correct the mixure. Anyways, I did this test. I took off fuel pressure regulator little vacuum hose, nothing happend, readings did not change. Then I blocked it with my finger so it would not suck any more air and then the reading went down to like 0.5v and climbed back to 1.28v after. But you are saying I should not care about the voltage, right ?
About the downstream one. Before buying it I asked if it gave any codes to ecu, he said it was not, the sensor is okay. He might lied of course. Anyways, have not check for resistance, voltage in that circuit, but I should. Is the downstream effecting mixure ?
And as I understand there are no fuse for heaters, the fuel relay might be the one. It's AVU engine.
Vin - WAUZZZ8L721006954
The upstream one has 5 wires. After a lot of reading I understood that voltage suppose to be jumping around 0.1 - 0.9 voltage to constantly correct the mixure. Anyways, I did this test. I took off fuel pressure regulator little vacuum hose, nothing happend, readings did not change. Then I blocked it with my finger so it would not suck any more air and then the reading went down to like 0.5v and climbed back to 1.28v after. But you are saying I should not care about the voltage, right ?
About the downstream one. Before buying it I asked if it gave any codes to ecu, he said it was not, the sensor is okay. He might lied of course. Anyways, have not check for resistance, voltage in that circuit, but I should. Is the downstream effecting mixure ?
And as I understand there are no fuse for heaters, the fuel relay might be the one. It's AVU engine.
Vin - WAUZZZ8L721006954
Edited by Klajoklis on Sunday 16th February 00:59
Edited by Klajoklis on Sunday 16th February 01:00
Edited by Klajoklis on Sunday 16th February 09:06
I had a look it's the same fuse for the heater on both lambda probes.
So if one is OK the fuse is not the issue.
Check there is power and ground for the heater element wires on both sensors.
Hopefully the good result in upstream sensor should show you what it should look like on downstream. One, where I suspect it will be missing. Likely damaged wire or corroded connection down under the car near the down stream sensor.
I'm trying to upload the diagrams but I just get error 522.
So if one is OK the fuse is not the issue.
Check there is power and ground for the heater element wires on both sensors.
Hopefully the good result in upstream sensor should show you what it should look like on downstream. One, where I suspect it will be missing. Likely damaged wire or corroded connection down under the car near the down stream sensor.
I'm trying to upload the diagrams but I just get error 522.
On the down stream probe, the feed that should be battery voltage is pin 1 and the ground Via the ECU is pin 2.
On the upstream probe feed is pin 3 and ground pin 4.
Upstream is defo a board band sensor so disregard any voltage from it, ecu measures amps to get mixture reading.
Focus on the heater on sensor 2 (down stream) first.
On the upstream probe feed is pin 3 and ground pin 4.
Upstream is defo a board band sensor so disregard any voltage from it, ecu measures amps to get mixture reading.
Focus on the heater on sensor 2 (down stream) first.
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