: 97 Deville - Sensor trouble, Running poor



Nickcruffin
05-29-05, 01:56 AM
Hear my sad story. I purchased a used Cadillac Deville 1997 last September. I has been running just great up until about 4 weeks ago. The service engine light came on and, to the Autozone guy, indicated that the Oxygen Sensors were bad. Bank one and two. I questioned this as it seamed unlikely that two identical sensors would go bad a the same time. But, a actual Cadillac service tech assured me that this is possible.



So like a good customer I purchased two Bosch OEM oxygen sensors and rented the handy dandy tool that AutoZone has. I replaced the two sensors and thought the problem would be over. NOT.



The service engine light came on again and again and again. Concurrent to this situation the car decided that it did not want to start. The starter would not run – every other electronic thing did but the starter would not turn over at all. This would last about 30 seconds to One minute. This would happen every other week once. I thought that the two situations were one. So I checked every thing I could think of. Then I found a thred on this site that told me that nomatter what I thought the starter was the problem. So, I removed the air intake manifold and removed the starter and took it to AutoZone and had it checked and fortunately the solenoid was bad. I replaced the starter and the care was whole again. ----- NOT.



The service engine light came on again but this time I got several fault codes. Lean condition bank one and two. The car runs bad getting very bad gas mileage. After the car runs for several hours it starts to run badly, not missing, just no power, until it literally can’t go any more. I pull over and kill the engine or it dies, I wait a minute then restart and the car runs again with power but very bad mileage. So on the advice of my Cadillac friend I first cleaned the Mass air Flow sensor, then replaced it. Not a thing changed, So I replaced the throttle position sensor. Again, no change, So I took the car to a Cadillac Specialist not the dealer. He found that I had a vacuum leak at the intake manifold. I had done a poor job of re-installing the intake manifold. So I purchased new gaskets cleaned the head and the manifold and re-installed the manifold. Eliminating the vacuum leaks.



This increased the time that it took for the service engine light to come on but did not solve the problem.



Back to the Cadillac specialist, he checked the car with his computer system and determined that I needed new spark plug wires. New wires were installed ----- nothing changed.



Back to the specialist – this time he is thinking that the cars computer was malfunctioning. I went to an auto salvage yard that specializes in Cadillac and picked up a computer. The new computer would not allow the car to start, another computer, no start, another computer, no start. After the third computer the yard man said that I would have to take the car and the new computer to a Cadillac dealer so that they could flash the computer. ---- I said that the reason that I am doing the work myself is to save money ---- Give me my money back. They did and gave me back my computer.



I installed the old computer and the car starts great. The next morning I take the car to the real Cadillac dealer to get this crap over with. The car had no codes for them to work with so they sent me on my way --- saying that I should drive it until it codes then return --- if it does not code just drive it. He also said that they had noticed that Bosch Oxygen Sensors don’t always work on Cadillac’s. If I get a code for one of the O2 sensors replace it and see what happens.



I drove off and the car ran great with great gas mileage and power, for three days. Then the light came on indicating a problem with O2 sensor Bank one. I replaced it and the car ran several days ok then the light came on again with the same code but in a few hours it went off again --- then on again then off in a few hours – it is now on again and I am getting sick of it. The car is running great and still getting good gas mileage. But, I keep thinking that the real problem will come back.



Can anyone give me some new ideas? I need HELP.



The car has 120,000 miles on it but the car is in perfect condition other wise.

My e-mail address is nickcruffin@aol.com

zonie77
05-29-05, 02:33 AM
Check the fuel pressure regulator.

dhs
05-29-05, 03:07 AM
Dam what a nightmare, how much did you spend in total?

mcowden
05-29-05, 11:32 AM
Nick -

It sounds like your problems can be attributed to several misdiagnoses, bad advice, ignorant salespeople, and faulty repairs. O2 sensors are a maintenance item, not something that goes bad because the car is a piece of crap. They don't last forever in any car. No way around that. Solenoids and starter motors also go bad. Sometimes they last forever, sometimes they don't. No way to tell. The biggest piece of advice I have for you is to check the codes yourself. If you have digital gauges, hold down the OFF and WARMER buttons for about 3-5 seconds, or with analog gauges, hold down OFF and passenger-side WARMER buttons for the same time. You will see the dash lights come on and then the codes will come up one at a time across the display. Be prepared to write them all down. They are 5 character codes that look like P0300 or B0472 or C2851. Once you have them, you can look them up here:

http://myweb.accessus.net/~090/dtcobd2.html

Then, once you've cross-referenced the code numbers with that web page, post the results here and someone will be able to tell you what's wrong and how to fix it. Don't rely on AutoZone or the dealership or a salvage yard counter person to tell you what's wrong with your car. You can trust yourself to check and look up the codes, and I think you'll get better advice here than any of those other places. The difference? Cadillac Forums has nothing to sell you. Everybody here is just a volunteer or enthusiast who's willing to lend a hand, probably because they've been in your shoes before.

So, all that said, it sounds like you have some codes in there right now. Go check them and post them here and we'll be glad to help. Just FYI, your car has 4 oxygen sensors. One in each cylinder bank exhaust manifold, one before the cat, and one after the cat. With 120k on the clock, you're bound to lose more than one of them. Sounds like you can handle the replacement yourself, so that'll save you some bux. If it needs another one, it needs another one. Once you've got it replaced, it should be running well again assuming that's why the SES light is on.

Ranger
05-29-05, 12:45 PM
To add to what Mcowden said and you seem to have aleady discovered, Bosch O2 sensors are said to not work well in Northstars. Stick with OEM sensors and you may well solve your problem. Also follow his advice on pulling the codes yourself. Cadillac is very good at self diagnosis. No other car has this ability. Keep us posted.

Nickcruffin
05-29-05, 03:45 PM
Thanks, here are the cods currently on my computer.

P0137, P0171, P0174, P0603, P1527, B0533 and B1552.

Nickcruffin
05-29-05, 03:53 PM
P0133 - Heated Oxygen Sensor (HO2S) Slow Response Bank 1 Sensor 1
P0171 - Fuel Trim System Lean Bank 1
P0174 - Fuel Trim System Lean Bank 2
P0603 - Control Module Long Term Memory Reset
I am gesseing that this is because the computer was out of the car for about 8 hours.
P1527 - Transmission Range to Pressure Switch Correlation
What is this about???
B0533 - Fuel Sensor Open/Shorted To B+
Where is this sensor???
B1552 - Keep Alive Memory (KAM) Error
Guessing this is also because of the time the computer was out of the car.

Nickcruffin
05-29-05, 03:54 PM
Buy the way it has a new fuel pressure regulator as well as all the above stuff

mcowden
05-29-05, 03:56 PM
Thanks, here are the cods currently on my computer.

P0137, P0171, P0174, P0603, P1527, B0533 and B1552.

You didn't mention whether these codes show up as History or Current, but I forgot to tell you about that part. Anyway, here's what they mean:

P0137 - Heated Oxygen Sensor (HO2S) Circuit Low Voltage Bank 1 Sensor 2
P0171 - Fuel Trim System Lean Bank 1
P0174 - Fuel Trim System Lean Bank 2
P0603 - Control Module Long Term Memory Reset
P1527 - Transmission Range to Pressure Switch Correlation
B0533 - Fuel Sensor Open/Shorted To B+
B1552 - Keep Alive Memory (KAM) Error

Can you take a look at the codes again and tell me if they're current or history? I suspect I know the answers, but want to be sure. Once you've written them down, you will probably see "PCM?" on the display. At that point, press the fan speed up button. Then you'll see "PCM CODES?" and you should press fan speed down. Next you'll see "PCM CLEAR CODES?" and then press fan speed up again. It will say "CODES CLEARED" followed by "PCM CODES?" Press the OFF button about 4 or 5 times until the dash goes back to normal operation, or just turn off the ignition. That will clear the PCM codes that are setting the SES light. Next time the light comes on, whatever code is in there is probably the one that's causing the light.

Let me know whether those codes are current or history before you clear them out though. We'll get this thing figured out.

Nickcruffin
05-29-05, 04:09 PM
only the P0131, is current.

Nickcruffin
05-29-05, 04:15 PM
sorry PO131 is the only current code, the P0137 was not a code I did not read my hand writing correctly.

Nickcruffin
05-29-05, 04:24 PM
So far I have not spent all that much money. It is just the agrivation of not knowing what to do. ---

mcowden
05-29-05, 04:34 PM
OK, so here's the diagnosis:

P0131 - Heated Oxygen Sensor (HO2S) Circuit Low Voltage Bank 1 Sensor 1

The B1S1 oxygen sensor is the one in the exhaust manifold for the rear bank of cylinders. That sensor is before the Y-pipe on the exhaust system. It's visible if you look behind the engine, way down at the exhaust manifold. On my '96 SLS, it took a long extension to get down there. Some people, maybe with different models or years, have been able to change that sensor from under the car. I got it from the top side. Either way, that one probably needs to be changed on your car. Take a look at it and make sure the wiring harness is in good shape. If it's plugged in and the wiring looks intact and undamaged, the sensor probably needs to be replaced. New OEM-brand sensors cost about $70-$80 each and can be installed in your garage pretty easily using an O2 sensor socket or crow's foot.

Did you clear the codes out? If you did and you get that O2 sensor replaced, the SES light should not come back and your car should run normally again. If it comes on again, check the codes with the car running, preferably after you've been driving normally for a while.

You can't just swap out a computer module on these cars. There are codes and calibration data that have to be synchronized between the original computer and a new one. That's why swapping computers didn't work. It can be done, but a dealership or third-party programming company has to do it and it will probably cost a few bux to get that done. You don't need a new computer. Yours is fine. You have the starter and intake fixed, the original computer is in place, and once this last O2 sensor gets fixed, you should be just fine again. Let us know what you do and how it works out, and any new codes if you get them.

Nickcruffin
05-29-05, 04:44 PM
That is what the Cadillac dealer said and i did repace that O2 sensor with a new one. but the code came back. the light has come on and gone off about three times. That is why i started this posting. --- Do you think that the Bosch O2 sensors are that bad. if so why has the bank 2 sensor 1 O2 not gone bad?

Note: I replaced the two O2 sensors first. Now the (Bank 1), (sensor 1) sensor twice.

Nickcruffin
05-29-05, 04:46 PM
Oh! the car is running normaly now even with the light on.

I will erase the code shortly.

mcowden
05-29-05, 09:30 PM
I would closely inspect the wiring for that B1S1 sensor and make sure everything is intact and undamaged. I don't think there's any non-destructive way to test continuity unfortunately, but a good visual inspection should be fine. If the wiring looks OK, that sensor should be replaced. If you have anything like the AutoTap (www.autotap.com) or other similar testing tools, they can show you the exact activity from that sensor so you can see what's going on with it. Maybe it's just faulty. Bad sensors do happen, especially if the anti-seize compound from the threads gets onto the sensor surface. Bad gas or antifreeze can also hose a sensor. It's also possible that while you had the intake leak, the system was running too lean and it just burned up the sensor.

I have heard a few stories about bad Bosch sensors, or that Bosch sensors don't work well in the Northstar application, as Ranger mentioned above. I have personally had good luck with them. I have all 4 Bosch sensors on my '96 SLS and they've been working just fine for 40k+ miles so far. I don't know anything about the advisability of mixing and matching OEM and Bosch sensors, so maybe someone more knowledgeable can speak to that. What I do know is you should inspect the wiring and fix as necessary or replace that sensor to clear up the code and SES light. Your mileage will probably get better with the O2 sensor working right.

Let us know what you do and how it turns out. It helps everyone if you tell us what you do, how you did it, how it turned out, how much it cost, and what shops or mechanics are good or bad. Good luck!

Nickcruffin
05-29-05, 11:15 PM
I have already replaced that O2 sensor twice i am not going to repalce it a third time in less than 6 weeks. --- where is the fuel sensor that is open to B+

Nickcruffin
05-29-05, 11:17 PM
maybe i should put the AC O2 sensor back, it did not look bad -- i know you can't tell anything from looks but it did not look any worse than the Bosch that was in there for only 2 weeks.

Nickcruffin
05-29-05, 11:20 PM
McCowden, thanks for telling me how to get and cancel the codes that is a great advantage. I have been going to AutoZone for them to read the codes.

Question: Why does the P0131 code not show up in history after i cancel the code? the other codes are in history.

Ranger
05-30-05, 01:35 AM
They only remain in history after they clear themselves from "current" by not detecting the fault for three ignition cycles. Then they go to history. When you clear the codes, you clear current and history.

LCLCLC
05-30-05, 02:30 AM
I occasionally get the B0533 fuel error on my 97. I clear it and after a while it will come back. I haven't researched it yet, I think it has something to do with the fuel guage sensor, which is inside the fuel tank.

As long as my fuel guage is still working ok, I'm going to ignore this error. I personally think when the tank is filled, the fuel level sensor is sending out too high a voltage and setting this error.

Caddys fuel sensors like to fail. As I said, as long as my guage works ok, I'm going to ignore this error. Especially since a replacement will involve dropping the fuel tank.

Nickcruffin
05-30-05, 06:31 PM
But, the P0131 code came on and went off at least three times before i cleared it this last time.