Bad O2 Sensor, Which One?

[shicks]

1998 ES300. Has 2 sensors, how do I tell which one is bad without bringing it to a service center?

Thanks,

Steve

[mburnickas]

1998 ES300.  Has 2 sensors, how do I tell which one is bad without bringing it to a service center?

Thanks,

Steve

←

You have three I think, not 2. There are 2 near engine and one after cat. I have a 98 and all are fine. You need to test them for volts and signal time.

I would test them since uless you are getting DTC or failed emmision, you should be fine; unless you have 500 million miles on the OEM ones.

Do a search on here since this came up about 2 months ago in this forum.

[shicks]

Thanks,

I did do a quick search, did not find what I was looking for. The car has about 80k miles. I am actually researching this for my Mom. She is about to get ripped off at a local tire shop. I assume it is a pretty easy DIY, but don't want to guess at which one is dead. Is is ok if she drives the car?

Steve

1998 ES300.  Has 2 sensors, how do I tell which one is bad without bringing it to a service center?

Thanks,

Steve

←

You have three I think, not 2. There are 2 near engine and one after cat. I have a 98 and all are fine. You need to test them for volts and signal time.

I would test them since uless you are getting DTC or failed emmision, you should be fine; unless you have 500 million miles on the OEM ones.

Do a search on here since this came up about 2 months ago in this forum.

←

[mburnickas]

Is the DTC (engine light on)? Are you having poor MPG?

I would go to autozone and have them hook up there scanner to the car. They do it for free.

My car has almost 90K miles and my scanner (snap-on) states that are fine.

The sensors are like $180 each for OEM and after market are much less.

The two in the engine bay are easy to so and the one by the cat, I have no clue.

This might help.

http://us.lexusownersclub.com/forums/index...n++sensor++test

or

http://us.lexusownersclub.com/forums/index...topic=24238&hl=

http://us.lexusownersclub.com/forums/index...n++sensor++test

[shicks]

Thank you for the links, this helps a lot.

Yes, she says the engine light is on, as far as MPG, I have no clue. I called NAPA and the have the one in the engine bay in stock for $105. I don't think she has an autozone near her. I may just buy one of each, and just eliminate which one is bad.

Steve

Is the DTC (engine light on)? Are you having poor MPG?

I would go to autozone and have them hook up there scanner to the car. They do it for free.

My car has almost 90K miles and my scanner (snap-on) states that are fine.

The sensors are like $180 each for OEM and after market are much less.

The two in the engine bay are easy to so and the one by the cat, I have no clue.

This might help.

http://us.lexusownersclub.com/forums/index...n++sensor++test

or

http://us.lexusownersclub.com/forums/index...topic=24238&hl=

http://us.lexusownersclub.com/forums/index...n++sensor++test

←

[steviej]

then how do you know the CEL or DTC indicates a bad O2 sensor. There are tons of sensors & codes that will set that idiot light off. It doesn't have to be specifically the O2 sensor. However, this is most common. You are better off saving your money, get the code read and address the specific problem.

what about PepBoys, or OReily's. Call any major autoparts store and see if they read codes for free.

Post the specific code and we will tell you what the code means.

steviej

[mburnickas]

then how do you know the CEL or DTC indicates a bad O2 sensor.  There are tons of sensors & codes that will set that idiot light off.  It doesn't have to be specifically the O2 sensor.  However, this is most common.  You are better off saving your money, get the code read and address the specific problem.

what about PepBoys, or OReily's.  Call any major autoparts store and see if they read codes for free.

Post the specific code and we will tell you what the code means.

steviej

←

I agree. Get the code read for free. You could spend the $$$ on 02 sensors and then it could be a bad gas cap seal!

[Toysrme]

1) Read the code / test the sensors by hand with a voltmeter.

2) NAPA is as overpriced on most of their parts as the OEMs are. Don't use them.

3) Replacing them is easy enough

[shicks]

Tanks everyone. The shop my Mom brought it to, must have read the code, which they are charging $40 for :-( They indicated a bad O2 senser. I have asked her to get the diagnosis, so I can replace the part next time I see her. I guess I am not sure if there is a seperate code for each sensor? If there is, when I get it, I'll look it up or post it on this thread.

Thanks,

Steve

1) Read the code / test the sensors by hand with a voltmeter.

2) NAPA is as overpriced on most of their parts as the OEMs are. Don't use them.

3) Replacing them is easy enough

←

[Toysrme]

There is.

[mburnickas]

Tanks everyone.  The shop my Mom brought it to, must have read the code, which they are charging $40 for :-(  They indicated a bad O2 senser.  I have asked her to get the diagnosis, so I can replace the part next time I see her.  I guess I am not sure if there is a seperate code for each sensor?  If there is, when I get it, I'll look it up or post it on this thread.

Thanks,

Steve

$40 sucks to read it when it is free at places, but it could be worse. Post the code (PXXX) here and we can help.

[steviej]

as Toysrme indicated, O2 sensors have multiple codes for each sensor. Keep in mind that just because the code indicates a bad sensor it may not be. It can be a problem upstream from the sensor that manifests itself with a faulty signal from the sensor.

you can look the code up yourself:

http://www.troublecodes.net/Lexus

but be careful. double check you codes with another source (here, another website, an actual shop manual or call a dealership). We have already found one misprint on this website.

steviej

[shicks]

Well, after all that she does not have a code, but a recipt that says "Oxygen Sensor Front Federal 1B". She does not live close by, but if I can save her $200 with a DIY I will, she may have an autozone for Advanced Auto I can take the car, to get the code.

Steve

[mburnickas]

Well, after all that she does not have a code, but a recipt that says "Oxygen Sensor Front Federal 1B".  She does not live close by, but if I can save her $200 with a DIY I will, she may have an autozone for Advanced Auto I can take the car, to get the code.

Steve

←

Well then how do they know what sensor to replace if they get no MIL or DTC cods? Unless they are testing it and it is getting weak, I have no idea.

[shicks]

Ok, I'm going to change the O2 sensor this weekend. Its Bank1 Sensor1. This is the sensor closest to the firewall, correct?

Do I need any special tools or instructions for the replacement?

Thanks,

Steve

[Toysrme]

You got it.

Bank 1 = right hand bank = odd bank = rear bank

You can do it with a wrench, or an o2 sensor socket, deep well socket, whatever comes easyest. Anti-sieze on the threads will help the next person that has to change them.

AFA splice in I always do it the right way (soldier + heat shrink), but there's nothing against crimping / twisting & using electrical tape if you do a good job (blah).

If you get the plug n play, obviously, that doesn't apply.

[monarch]

Ok, I'm going to change the O2 sensor this weekend.  Its Bank1 Sensor1.  This is the sensor closest to the firewall, correct? Do I need any special tools or instructions for the replacement?

←

No special tools if you bought genuine Toyota (Denso) sensors because they are designed to look and fit exactly like the factory originals, although it can sometimes be a bit difficult to figure out how to loosen the electrical connector on the sensor. Spray the sensor mounting bolt with a penetrating lube as it is likely to be corroded and use a six point socket when removing it. In extreme cases of corrosion the mounting bolt may need to be sawed off.

[shicks]

Ohhh...making me nevous. I have done this several times to other cars, never had that problem. Is this location hard to reach? This is my Moms car, she is out of state, so I'll see this area for the first time.

One other question not related. When should the timing belts and spark plugs be changed? She has 90k on the clock.

Thanks,

Steve

Ok, I'm going to change the O2 sensor this weekend.  Its Bank1 Sensor1.  This is the sensor closest to the firewall, correct? Do I need any special tools or instructions for the replacement?

←

No special tools if you bought genuine Toyota (Denso) sensors because they are designed to look and fit exactly like the factory originals, although it can sometimes be a bit difficult to figure out how to loosen the electrical connector on the sensor. Spray the sensor mounting bolt with a penetrating lube as it is likely to be corroded and use a six point socket when removing it. In extreme cases of corrosion the mounting bolt may need to be sawed off.

←

[Toysrme]

Timing belt & water pump need to be every 90,000m / 72months.

Spark plugs every 60,000m / 48months.

1998 Camry

90,000 Miles - 72 Months

Replace engine oil and oil filter

Replace engine air filter

Replace engine coolant

Rotate tires

Inspect the following:

Ball joints and dust covers

Brake linings/drums and brake pads/discs

Drive belts

Drive shaft boots (re-torque flange bolts)

Exhaust pipes and mountings

Fuel lines and connections, fuel tank band and fuel tank vapor vent system hoses

Fuel tank cap gasket

Rack and pinion assy. for leakage

Steering linkages

Transmission and differential oil

Additional Maintenance Items for Special Operating Conditions:

Driving on Rough, Muddy or Snow-Melted Roads

Inspect nuts and bolts on chassis and body

Extensive Idling or Low-Speed Driving for Long Distances

Replace timing belt

Towing a Trailer or Using a Camper or Car-Top Carrier

Inspect nuts and bolts on chassis and body

Replace transmission and differential oil

Go download the '94 Camry repair manual & deal with the changes, register the car on Lexus.com & get their schedule - which happens to be the same as the toyota literature http://www.toyotaownersonline.com/parts-service/diy.php, or download the full repair manual for techinfo.toyota.com for $10 a day.

I've never found it hard to reach the rear o2 sensor. If you're really concerned about it practicing on the front one is bound to be the best advice you'll hear on the subject LoL!

(Be sure to do it when the car is cool. Exhaust manifolds are something you don't want to bump into many times LoL!)

[cyberflyer]

Be careful there is a big difference between an 02 sensor and a fuel/air ratio sensor ..... they are not interchangeable.