O2 Sensor Problems already??
#16
My fuel economy went up after I put in new sensors. Not much, but around 2 mpg. After a certain point, they become less accurate. My concern was less about the savings the the pump, and more about an imprecise mixture of air/fuel. In this case, it looks like the engine was running a bit rich with the old O2 sensor. More rich=more wear on the engine.
Most O2 sensor companies recommend replacement as part of a tuneup, just like you would change your spark plugs even if they weren't throwing codes after a certain mileage.
I have around 140k miles, and the cost war around $120, so about 2 tanks of gas.
I wouldn't touch the down stream (after cat) sensors unless they were throwing codes, they exist as a sort of "pass/fail" for emissions testing, it doesn't "tell" the engine to make changes on the fly. And even if you were getting codes on the downstream sensors, I'd probably look into getting a "cheater" plug that fooled the sensor before I replaced the cats and sensors.
#17
Lexus Test Driver
iTrader: (1)
I think it's wise for the upstream o2 sensors (before the catalytic converters)
My fuel economy went up after I put in new sensors. Not much, but around 2 mpg. After a certain point, they become less accurate. My concern was less about the savings the the pump, and more about an imprecise mixture of air/fuel. In this case, it looks like the engine was running a bit rich with the old O2 sensor. More rich=more wear on the engine.
Most O2 sensor companies recommend replacement as part of a tuneup, just like you would change your spark plugs even if they weren't throwing codes after a certain mileage.
I have around 140k miles, and the cost war around $120, so about 2 tanks of gas.
I wouldn't touch the down stream (after cat) sensors unless they were throwing codes, they exist as a sort of "pass/fail" for emissions testing, it doesn't "tell" the engine to make changes on the fly. And even if you were getting codes on the downstream sensors, I'd probably look into getting a "cheater" plug that fooled the sensor before I replaced the cats and sensors.
My fuel economy went up after I put in new sensors. Not much, but around 2 mpg. After a certain point, they become less accurate. My concern was less about the savings the the pump, and more about an imprecise mixture of air/fuel. In this case, it looks like the engine was running a bit rich with the old O2 sensor. More rich=more wear on the engine.
Most O2 sensor companies recommend replacement as part of a tuneup, just like you would change your spark plugs even if they weren't throwing codes after a certain mileage.
I have around 140k miles, and the cost war around $120, so about 2 tanks of gas.
I wouldn't touch the down stream (after cat) sensors unless they were throwing codes, they exist as a sort of "pass/fail" for emissions testing, it doesn't "tell" the engine to make changes on the fly. And even if you were getting codes on the downstream sensors, I'd probably look into getting a "cheater" plug that fooled the sensor before I replaced the cats and sensors.
#18
Pole Position
Thread Starter
Sorry i havent been online for a few days....thanks for all the help!
I got under the car, and saw that the o2 sensor was bent almost 45 degrees! Whatever i hit on the freeway bent it, and tore up some of that heat shield next to the sensor.
It took a few days for the light to come on though. I ordered an universal Denso and plan on hitting it out after my vacation
I got under the car, and saw that the o2 sensor was bent almost 45 degrees! Whatever i hit on the freeway bent it, and tore up some of that heat shield next to the sensor.
It took a few days for the light to come on though. I ordered an universal Denso and plan on hitting it out after my vacation
#19
They're used for the DOWNSTREAM O2 sensor (after the cat converter)
The downstream oxygen sensor is basically for the purpose of emissions testers to let them know something is wrong with the catalytic converter. It's a pass or fail sensor, it doesn't tell the car to adjust fuel delivery.
#20
Lexus Test Driver
iTrader: (1)
A cheater plug was just my name for them, but you can either put an electrical resistor in between where the O2 sensor goes to the harness, or you can space the O2 sensor away from the exhaust so it "trick" the ECM into believing everything is okay with the catalytic converter.
They're used for the DOWNSTREAM O2 sensor (after the cat converter)
The downstream oxygen sensor is basically for the purpose of emissions testers to let them know something is wrong with the catalytic converter. It's a pass or fail sensor, it doesn't tell the car to adjust fuel delivery.
They're used for the DOWNSTREAM O2 sensor (after the cat converter)
The downstream oxygen sensor is basically for the purpose of emissions testers to let them know something is wrong with the catalytic converter. It's a pass or fail sensor, it doesn't tell the car to adjust fuel delivery.
#21
If you're not getting any sort of codes, leave it be. Your car won't run any better replacing the downstream O2 sensors with new ones.
There's always the "right way" to fix it if you're getting those codes, but you're likely looking at a new catalytic converter set up (around $1,500 through a dealership) and 2 new O2 sensors. Most likely all of the above if you've got well over 100k miles on the car. If you're not doing the work yourself, you're looking at about $2,000 worth of work to get rid of that check engine light for the emission tester.
Or a $12 spacer plug.
#22
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Afr sensor
Please make sure that if your car has AFR sensor (air fuel ratio) then you replace it with an AFR and if you have oxygen sensor then r,eplace it with oxygen sensor since signal detection circuitry inside the ECM looks for a specific voltage range for feedback signal. If the feedback signals are different then ECM will throw cel light and could also lead to damaging the ECM. Thanks
#23
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Hi,
I'm also getting two codes, P0138 and P0158, I had some problem with the harness in engine bay and some wires were patched after they were frayed. It's a sc430, yr2002
P0138 is high voltage in the B1S2 circuit. Would you happen to have the ecu resistance based Troubleshooting steps are same as mentioned above for diagnosing P0158
Greatly appreciate your help in advance
Thanks
I'm also getting two codes, P0138 and P0158, I had some problem with the harness in engine bay and some wires were patched after they were frayed. It's a sc430, yr2002
P0138 is high voltage in the B1S2 circuit. Would you happen to have the ecu resistance based Troubleshooting steps are same as mentioned above for diagnosing P0158
Greatly appreciate your help in advance
Thanks
#24
my LS 430 with 84,000 miles just needed one sensor replaced. Parts and labor and tax totaled about $550. That seems high, but my warranty covered most of it.
#26
Racer
#27
Driver School Candidate
Get some beers, read some tutorials, replace, drink more beer. You don't even need a garage, and the tools to do the job cost like $30. Plus $15 for the beer. I prefer Natty Ice.
#30
Instructor
My weekly driving is short distances (4-8km per engine-on cycle).
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