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02 sensors?


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Long time since a break down eh? My kid drove this car like he stole it for 2 years now I have to tend to it. NOT 95 SLS It's a 1996 Eldorado Not ETC.

Code says, P0140 Bank one sensor 2 Current

Code says P0154 Bank two sensor 1 Current (this one is new)

Question is. Ok I think Front is part with the belt Right?

Question is: If Front is part with belt is Left of engine fwd as in the car?

Question is: Is sensor 1 like 1st one in system going down the line? And is sensor two the next one going down that line like around the Converter?

I want to change the PO154 one 1st and see what happens. The PO140 Just started to show up while I was running codes over and over and resetting them. I just pulled this car out of the Barn after sitting 2 years.

MC

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You pretty much have it.

Bank one is the firewall side. Sensor one is closest to the head.

If they are installed, bank one, sensor two will be in front of the catalytic converter and bank one, sensor three will be directly behind the catalytic converter.

Bank two on a sideways Northstar will only have the sensor identified as bank two, sensor one.

At some point in the production history, I believe all these different O2 sensor locations used the same part number. So, if replacing a sensor in one location does not help your situation, you probably still have a working sensor to use at another location. Make sense??

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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MC,

I also got a bad sensor code so I went into the onboard computer and sure enough, that sensor was just sending a signal of 0. Rockauto.com was the lowest cost for a new sensor. Use the this code: ROCKVAL1 for 5% off.

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Ok thanks, I have had good luck with Rockauto for sure. Many parts always fit and good service so that is a possibility. I didn't check the value of the sensors in question, seems like all the O2 sensors are giving out. I may buy two if they are all the same.

Is an O2 sensor an 02 sensor? Or are they specific to the location? So many choices!

Upstream, downstream and prices and makes. TRU-TECH Part # SG273T

Two required.; Upstream Sensor

$36.99 $0.00 $36.99

DENSO Part # 2344018

Front

$38.89 $0.00 $38.89

DENSO Part # 2344025

Rear

$41.79 $0.00 $41.79

STANDARD MOTOR PRODUCTS Part # SG273 {UPSTREAM SENSOR}

Two required.; Upstream Sensor

$55.79 $0.00 $55.79

BOSCH Part # 13474 {Oxygen Sensor - OE Type Before Catalyst}

Two required; One sensor located in each manifold. Interval=100000

$57.79 $0.00 $57.79

STANDARD MOTOR PRODUCTS Part # SG274 {DOWNSTREAM SENSOR}

Two required.; Downstream Sensor

$60.79 $0.00 $60.79

Reason I ask, The kid changed one I just replaced, he made it easy by just cutting the wires, when the code still set I asked what one he changed? Same one I did a month prior, the good one! (The top one by the firewall, PITA!!!) MC

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The downstream oxygen sensors are different from the upstream Sensor 1 oxygen sensors. The upstream oxygen sensors are part of the closed-loop fuel injection mixture control, while the downstream one just monitors cat efficiency.

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You said your O2 sensors are going, recall that some compounds will damage O2 sensors, is he using any gas additives, lead or silicone?

I have an O2 sensor socket that allows you to remove them without cutting the wires, I am sure you are aware of those sockets.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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The downstream oxygen sensors are different from the upstream Sensor 1 oxygen sensors. The upstream oxygen sensors are part of the closed-loop fuel injection mixture control, while the downstream one just monitors cat efficiency.

Yea I have the socket. In stock LOL I still am kind of unsure about what ones to change. I read they have a expected service life of 30 to 50K miles. So I am way past due. These two trip pretty often so I will try to hit the right ones, if I miss that only leaves one to change. MC

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You said your O2 sensors are going, recall that some compounds will damage O2 sensors, is he using any gas additives, lead or silicone?

I have an O2 sensor socket that allows you to remove them without cutting the wires, I am sure you are aware of those sockets.

Well I parked this car like more than a year ago when the kid went into Marines. Had a antifreeze smell to it loss off coolant never found the leak. Put in new fluid and tabs, no leak. Today I consider someone said silicone may wear out 02 sensor, so i did compression check on all cyl throttle open, all plugs out 4 pumps got like 190's to 200 all the way no leak downs.

So I went to buy sensors and I see a puddle, no find, go home let idle shut off and BOOM Pinhole leak from bottom hose squirting onto water pump bottom! But now it is more than a pin hole!

Always find a leak just after you put new fluid in.

I see SM says that left and right are determined as you stand to rear (Drivers side) of engine but I don't see anywhere what bank is 1 and what bank is 2. I know someone said bank 1 is drivers side, i just got to be sure.

MC

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....

I see SM says that left and right are determined as you stand to rear (Drivers side) of engine but I don't see anywhere what bank is 1 and what bank is 2. I know someone said bank 1 is drivers side, i just got to be sure.

MC

Bank one always contains cylinder number one.

On most if not all GM V engines, bank one will be on the right side when you are standing at the flywheel end of the engine.

Mounting an engine transverse throws the driver's side vs passenger's side rules off by 90 degrees.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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You said your O2 sensors are going, recall that some compounds will damage O2 sensors, is he using any gas additives, lead or silicone?

I have an O2 sensor socket that allows you to remove them without cutting the wires, I am sure you are aware of those sockets.

Well I parked this car like more than a year ago when the kid went into Marines. Had a antifreeze smell to it loss off coolant never found the leak. Put in new fluid and tabs, no leak. Today I consider someone said silicone may wear out 02 sensor, so i did compression check on all cyl throttle open, all plugs out 4 pumps got like 190's to 200 all the way no leak downs.

So I went to buy sensors and I see a puddle, no find, go home let idle shut off and BOOM Pinhole leak from bottom hose squirting onto water pump bottom! But now it is more than a pin hole!

Always find a leak just after you put new fluid in.

I see SM says that left and right are determined as you stand to rear (Drivers side) of engine but I don't see anywhere what bank is 1 and what bank is 2. I know someone said bank 1 is drivers side, i just got to be sure.

MC

Standing in front of engine(passenger side of car,where the drive belt is)left side of engine,closest to firewall are#'s 1-3-5-7...Bank1...
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I read they have a expected service life of 30 to 50K miles.

I had 125K on my '92 and 107K on my '97 and never replaced or had a problem with the O2 sensors.

Today I consider someone said silicone may wear out 02 sensor

To quote the Guru, "Silicone is instant death to O2 sensors"

On another note, aren't 2 sensors (probably the CAT sensors) heated as opposed to the manifold sensors which are not?

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Bank one cylinder one! Now that is my language! I can now remember that! Hey! Learn something new every day! Thanks! That makes it easy. They could have said that in the book eh? I understood the right side is bank one, but I gotta know why they call it that! LOL

Well, I haven't looked for the locations. I see the bank 2 sensor 2 I'm not so sure where sensor 1 is though. I normally buy one and go looking for what I have ha ha. But I am all hyped up that I can get this back on the road. I have an SUV now and it don't get that good of mileage.

My Urban assault vehicle 19 MPG Hwy.

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I have new struts, dogbones, ready to go on and possibly get new leather inside and it will be/look as new with 130K miles on it. I have DTS wheels I got off of Cardio Doc. Wonder where he got to? MC

Can I hijack my own thread?

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Cardio-doc as you know sells wheels on Ebay, here is his store:

http://motors.search.ebay.com/_W0QQsassZcardioQ2ddoc

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Bank one cylinder one! Now that is my language! I can now remember that! Hey! Learn something new every day! Thanks! That makes it easy. They could have said that in the book eh? I understood the right side is bank one, but I gotta know why they call it that! LOL

Well, I haven't looked for the locations. I see the bank 2 sensor 2 I'm not so sure where sensor 1 is though. I normally buy one and go looking for what I have ha ha. But I am all hyped up that I can get this back on the road. I have an SUV now and it don't get that good of mileage.

....

There is not a bank two sensor two.

If your car has 4 sensors, they will be identified as B1 - S1, B1 - S2, B1 - S3, and B2 - S1.

Sensor one will be within inches of the heads; sensors two and three will be catalytic converter inlet and outlet respectively.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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Heated Oxygen Sensors (HO2S)

Important

Only early model year production are equipped with a Pre-Converter (B1S2) Heated Oxygen Sensor (HO2S). If equipped, this HO2S is connected to the PCM and vehicle electrical system but is no longer monitored or diagnosed.

The three or four oxygen sensors are mounted in the exhaust system where they monitor the oxygen content in the exhaust stream. There is an oxygen sensor mounted in each exhaust manifold and one on the downstream end of the catalytic converter. Some early production vehicles also have an oxygen sensor located at the front of the catalytic converter (Pre-converter). The oxygen sensor located in the front exhaust manifold is the Bank 2 Sensor 1 (Front bank) sensor. The oxygen sensor located in the rear exhaust manifold is the Bank 1 Sensor 1 (Rear) sensor. The oxygen sensor located in the Y-pipe ahead of the catalytic converter is the Bank 1 Sensor 2 (Pre-converter) sensor. The oxygen sensor located in the catalytic converter outlet is the Bank 1 Sensor 3 (Post-converter) sensor.

An oxygen sensor acts like a battery because it creates its own signal voltage once it reaches operating temperature. This voltage is produced when the oxygen content in the exhaust stream is different than the oxygen content in the atmosphere. A lean condition (high oxygen content in exhaust) will produce a low voltage (near 0 volt) and a rich condition (low oxygen content in exhaust) will produce a high voltage (near one volt). The PCM provides a reference signal voltage (0.45 volt) and a ground to the sensor. The PCM reference voltage is necessary because the oxygen sensors do not provide their own voltage until they reach operating temperature.

The oxygen sensors also incorporate a heating element inside of the sensor housing. This heating element is energized with the ignition On and allows the sensors to reach operating temperatures quickly. The PCM can then use oxygen sensor information sooner after engine startup.

The PCM uses oxygen sensor information during Closed Loop operation to constantly adjust fuel control to reduce exhaust emissions. Because the oxygen sensors provide information sooner after engine startup, exhaust emissions are reduced. Faulty oxygen sensors will cause various driveability conditions and will set a DTC.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I guess I mis spoke when I said Bank 2 sensor two. However, the reply's got me right on tract. Now I know where all the sensors are as i have laid eyes on them. The bank 2 I need to change is kind of behind the fans in a hole. And the other will be before the cat. No too bad.

I think it was the rockauto site that lead me to believe there were two sensors on left bank, by what they say. SO I was like looking for a sensor that was not there.

I'm glad I asked these stupid questions. Helps a lot when you understand the Caddy lingo.

Actually the car runs fine. But no matter how many times you reset the codes they come back quick and I read that you can damage the cat running with bad sensors.

I'll tackle this when I get home, I work on the road. No further questions! Thanks a heap you guys gave me all the info I need! Thanks thanks thanks. MC

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FIXED!

Thanks a lot. Just to report back in. I considered Rockauto but same price at AutozZone but cheaper, by like $40 after you add in the savings card return. And AZ got a new computer today that is color and shows on a diagram exactly where the sensors are. Pretty cool. 1 YR warranty on the parts too.

I replaced bank 2 sen 1 1st and got no codes for like 50 miles, then Bank 1 sen 2 came back with a PO1130 which was a insufficient data on same sensor so I replaced that and looks OK no codes.

Like I said, I had the car in storage because everyone thought I had a head gasket leak, that turned out to be a Lower Rad Hose squirting water through a pinhole onto bottom of waterpump.

But now All I have to do is run out the gas with STABIL in it and refuel with 93 again and I should be OK.

MC

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