jinxed45 Posted July 10, 2004 Report Share Posted July 10, 2004 I took my 1997 Eldorado with 109k to a PepBoys.. Had them change the "primary O2 Sensor," one in manifold.. and the post-cat O2 sensor. I'm still getting the P0146 code.. the post-cat.. I went back and asked if they changed the correct one.. they weren't sure.. they asked the guy that did it.. he said he wasn't sure, but he changed the one on the LEFT.. "That's the post-cat one" he says.. so I said ok. Well.. why am I getting the same code? He told me I didn't clear the LONG TERM memory.. I only cleared the SHORT TERM.. My question: How do I clear the long term memory for the codes? Or is there really no such thing? And is the LEFT side the post cat or the pre? Thanks~! Link to comment Share on other sites More sharing options...
adallak Posted July 10, 2004 Report Share Posted July 10, 2004 I think Long term memory and short term memory is BS. Asking questions the guy who said that is wasting the time. Besides, he may think the car begins with the exhaust pipe, so it would be really hard for him to to say what sensor he changed pre cat or post cat! The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
wontgoslo Posted July 10, 2004 Report Share Posted July 10, 2004 bank 1 sensor 3 thats the one after the cat. it also monitors your cat. maybe its telling you to replace it. Link to comment Share on other sites More sharing options...
Regis Posted July 11, 2004 Report Share Posted July 11, 2004 Only thing your caddy should be in a Pep Boys bay for is tires and nothing else. Those guys may be nice sincere guys but they don't know squat about a northstar engine. Way too complicated of an engine (expensive too). -kg "Burns" rubber " I've never considered myself to be all that conservative, but it seems the more liberal some people get the more conservative I become. " Link to comment Share on other sites More sharing options...
jinxed45 Posted July 11, 2004 Author Report Share Posted July 11, 2004 i asked the "mechanic" what he needed to get a job there... he said "nothing." literally... i'm worried now.. where is the O2 sensor.. can i see it by jacking up the car? Thanks... Link to comment Share on other sites More sharing options...
jschunke Posted July 11, 2004 Report Share Posted July 11, 2004 If you took it to the stealer you would have billed for a new exhaust, engine, trans, and commision. The Pep Boys mechanic probably changed the sensor you asked him to change and charged a reasonable amount. You don't go to a Quick Check looking for fresh fish, do ya? Link to comment Share on other sites More sharing options...
Logan Posted July 11, 2004 Report Share Posted July 11, 2004 Bank 1, sensor 3. That would be the O2 sensor mounted after the cat con. Heres the diagnostics... DTC P0146 HO2S Circuit Insufficient Activity Bank 1 Sensor 3 Circuit Description The PCM provides a 0.45 volt reference to the oxygen sensor on CKT 1668. When the Oxygen Sensor reaches operating temperature it will generate a counter voltage that will vary based on the amount of oxygen in the exhaust. The post-converter heated oxygen sensor is located in the exhaust after the catalytic converter. A lean exhaust will generate a low voltage and cause the 0.45 reference to move lower. A rich exhaust will generate a high voltage and cause the 0.45 reference to move higher. If the oxygen sensor cannot respond under the test conditions and generate a voltage greater than 0.609 volt or less than 0.307 volt, it will set a DTC P0146. Possible causes of DTC P0146 are: Open in CKT 1668 or 1669. Short to voltage on CKT 1668 or 1669. Oxygen sensor that malfunctions. An ineffective oxygen sensor heater. A poor HO2S ground. Conditions for Setting the DTC Test Conditions DTCs P0117, P0118, P0122 and P0123 not set. Coolant temperature 75°C (167°F) or greater. Throttle between 2.2 and 81.6 degrees. (Calculated) Throttle position switch open. Engine speed between 800 and 3000 RPM. Failure Condition Oxygen sensor voltage stays between 0.307 volt and 0.609 volt for 250 out of 300 seconds, oxygen sensor voltage not toggling. Action Taken When the DTC Sets The PCM will illuminate the Malfunction Indicator Lamp (MIL) after two consecutive drive trips that the diagnostic runs and fails. The PCM will record operating conditions at the time the DTC sets. This information will be stored in the Freeze Frame and Failure Records. A first failure of this DTC will store in Last Test Failed but not History. Conditions for Clearing the MIL/DTC The PCM will illuminate the Malfunction Indicator Lamp (MIL) after two consecutive drive trips that the diagnostic runs and fails. The PCM will record operating conditions at the time the DTC sets. This information will be stored in the Freeze Frame and Failure Records. A first failure of this DTC will store in Last Test Failed but not History. Diagnostic Aids Notice Do not solder heated oxygen sensor wires. Soldering the wires will result in the loss of the air reference to the sensor. Refer to Engine Electrical for proper wire and connection repair techniques. A loose HO2S or one with a poor exhaust ground may cause this DTC to set. Before replacing an HO2S always check the resistance of the sensor ground. On a COLD engine, measure the resistance between the HO2S low circuit and the PCM ground at the PCM connector. If the resistance measures more than 500 ohms (typically less than 50 ohms), remove the sensor and check for corrosion at the HO2S sensor threads. Clean the HO2S sensor threads, apply a coating of anti-seize compound (5613695 or equivalent) and torque the HO2S sensor to the proper torque. Recheck HO2S ground resistance and replace any sensor with resistance above 500 ohms. Test Description Number(s) below refer to the step number(s) on the Diagnostic Table. Voltage on the scan tool should fluctuate above 0.6 volt and below 0.3 volt. If voltage remains above 0.6 volt, check the Post HO2S High circuit for a short to voltage. If voltage remains below 0.3 volt, check the Post HO2S High circuit for a short to ground. Measuring voltage with a voltmeter will isolate a sensor problem from a PCM wiring problem. Logan Diagnostic LLC www.airbagcrash.com www.ledfix.com www.ledfix.com/yukontaillightrepair.html www.ledfix.com/ledreplacements.html www.ledfix.com/j42385toolrental.html Link to comment Share on other sites More sharing options...
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