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2002 OLDSMOBILE ALERO, WONT GO IN READY STATUS FOR EMISSIONS TESTING, STATES HEATED O2 SENSOR, O2 SENSOR AND CATALYST NOT READY HAVE DRIVEN OVER 2000 MILES,AND COMPLETED DRIVE CYCLE,STILL WONT GO INTO READY STATUS TO PASS EMISSIONS, CHECK ENGINE LIGHT IS ON READS CODE P0440 HAVE CHANGED PURGE VALVE, GAS CAP,AND THE FUEL FILTER, LIGHT STAYED OFF FOR 2 DAYS CAME BACK ON. ANY HELP APPRICAITED.
Broken evap line/port on fuel pump. Or leaking fuel pump o-ring
check the EVAP canister it is right next to fuel filter could be pcm needs update to fix false codes. Here is a old hillbilly trick that may help put saliva on the seal of gas cap when you fill up every time that may work for you.
there is still a small leak, the shop thats doing the testing can repair it? right? Usually these things are just one item, you may have more than one.
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catalytic converter .
In order to control emissions, a catalytic converter converts any harmful exhaust emissions into harmless water vapor and carbon dioxide.
The powertrain control module (PCM) has the capability to monitor this process by using a rear-heated oxygen sensor (HO2S 2). The HO2S 2 , located in the exhaust stream past the catalytic converter, produces an output signal which indicates the storage capacity of the catalyst. This in turn indicates the catalysts ability to convert the exhaust emissions effectively. If the catalyst is functioning properly, the HO2S 2 signal will be far less active than the signal produced by the front oxygen sensor (O2S 1).
You have 8 I/M or Emission Monitors that have to run clear
BEFORE you can go to inspection
Your Catalyst Efficiency comes from the switching comparison
of the front & rear oxygen sensors being out of range
Until you resolve the rear O2 Sensor Heater Issue you won't
know if the cat is good or you have other problems
You need professional scan tool software & a long road test
to even find a problem,then component test,which apparently
wasn't done when they hung the new rear sensor on based on a code
The catalyst is able to oxidize hydrocarbons (unburnt fuel) at about 600 degrees. The air injection pump routes fresh air straight to thecat to aid in speeding up the light off time. once there, the cat stays warm enough to oxidize at all times. The oxygen sensors have heater circuits built in (4 wire vs. the earlier 2 wire O2 sensors, this is why they're referred to as HO2S; Heated O2 Sensors) As for the term "Not Ready" this applies to one of the monitors run by the PCM the Emissions Monitor. EGR flow, O2 sensor operation, catalyst temp are all monitored by the PCM so it can decide whether it will run in Open Loop (ignoring O2 sensor inputs) or Closed Loop (adjusting fuel trim by reading the O2 Sensor input) To change a monitor status from "Not Ready" to "Ready" is as simple as driving as per TRIP guidelines. Once a TRIP is completed (a TRIP is an acronym don't remember what it is right now, but a TRIP is different than a drive cycle) then monitors will have completed and be "ready" unless there is a problem in which a DTC will be stored along with freeze frame data (Mode 6) and if enough key cycles for the individual code (Some are instantaneous, some are 3 key cycles, some are 5, and some are successive key cycles), then a MIL or Check Engine Light will turn on as well. Hope this helps
To start with, if the check engine light is not on, you probably don't need to check any of the components. The engine and systems have to get up to operating temp and go thru the closed loop program a few times before the exhaust can be checked. The printout you have says the engine and exhaust have not been hot enough yet. The correct process to make the components ready to test is - drive at 55 mph for at least 12 min with no stops or variance in speed. Then 0-35 mph at least 4 times, and make sure you make complete stops each time. This should run the emissions system thru a complete drive cycle. Some state testing is different so check with your state.
One possible issue is a faulty thermostat. If the engine is not getting up to normal temp the emissions system will not go into closed loop. I know its hot in Nevada now so thats just a suggestion. The O2 sensors have heaters to make the exhaust gas hot quick so that the sensors can work. Is the check engine light coming on - or is it just that the exhaust gas is not hot enough for the test equipment ?
monitoring to detect ignition and fuel related misfires that may cause emissions to increase and/or damage to the catalytic converter.
Fuel System Monitoring to detect changes in fuel mixture that may cause emissions to increase.
Comprehensive Component Monitoring to detect any major faults in engine sensors that may cause emissions to increase.
The OBD monitors that only run under certain conditions include the EVAP monitor, HEGO monitor (Heated Exhaust Gas Oxygen sensor), and the Catalyst Efficiency monitor.
Did You Unplug The Battery Both Sides And Let Sit For #0 Minutes? Or Did You Scan With A scanner And Clear The Existing Codes? Most of The Time When You Correct The Issues With Your ECM It Will Clear Up But Just Like A computer You Must Restart It to Make Changes !! Hope This Helps !!
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The not ready may be for a HEATED O2 sensor and HEATED catalyst. Since these cars are not equipped with the HEATED versions, they would never be ready.
Just maybe your O2 sensors are not operating properly. They may be requiring your engine to heat them up to get upper temperature readings but not lower. You can easily diagnose these and all other sensors and problems by purchasing a Hains manual at your local Auto Zone or Advance auto store which will greatly aide you in diagnosing all your auto needs. And the fault symptom index at the beginning of the book will ease your troubles with professional one on one advice with step by step instructions. Its like having your own ASE certified mechanic at your finger tips. Good luck.
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