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Pete, Technician
Category: Car
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Experience:  17 years automotive training and experience.
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Volvo S80 2.9: I bought a 2002 S80 2.9 for my son. The car

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I bought a 2002 S80 2.9 for my son. The car had a CEL but ran really strong and had no issues during the test drive and the body and interior were better then average. I negotiated what I feel was a good price and bought the car. While driving home I noticed a slight bucking feeling when stopped with the foot on the break. Idle, is steady at about 700.

I changed the oil and filter, fuel filter, spark plugs where in good shape and are Volvo plugs, changed the plug boots and am an my first tank of injector cleaner.

Disconnected the battery to correct the previous owners improper installation and the CEL went out. Inspection failed due to the Cat and Evap "Not Ready". Just now getting the O2Sensor "Not Ready".

Here are the codes. I am thinking 02 Sensor? Do you think its worth taking them out and bench testing them?

P2096 - Post Catalyst Fuel Trim System Too Lean Bank 1

P2098 - Post Catalyst Fuel Trim System Too Lean Bank 2

And 3 not ready modules,

Catalyst monitoring - INC
Evap system - INC
Oxygen sensor Monitoring - INC

I really just need some direction.


Hi Mike,my name is XXXXX XXXXX I am a professional here at Just Answer/Pearl. I noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.

With the codes you have set here most likely this isn't oxygen sensors at fault (they can fail and cause these codes in some cases but usually only one of the codes or one bank of the engine and not both at the same time like this).

The lean codes indicate the engine is running lean,this can be the cause of the bucking feel you have noticed as well.I would check over the engine to see if there are any visible vacuum leaks noticed,if no leaks are noticed with hoses or components then a smoke test should be done to where smoke is injected into the intake and any leaking out of an area where it shouldn't is the source of the leak needing repaired (possibly intake gaskets).

If no vacuum leaks are present next I would have the fuel supply system tested to see if this is a lack of fuel issue possibly due to a weak fuel pump or restricted fuel injectors.The fuel pressure would need tested at key on,idle and when revved up to see if this is a fuel supply fault.I can tell you how to test this if you have a fuel pressure test gage just let me know.If the pump is found to be weak it would need replaced.Running the injector cleaner through it may correct this as well and may need done a few times.

As for the monitors not resetting after the lean issue is corrected and the fault codes are erased/cleared out you can try this procedure below as this will usually help speed up the monitor tests so you can have the emissions testing done.

Cold Start
The barometric pressure (BARO) is more than 81 kPa.
The engine coolant temperature (ECT) is between (41-86°F).
The intake air temperature (IAT) is between (41-86°F).
The start-up ECT and IAT are within (16°F) of each other.
The battery voltage is between 9-16 volts.
The fuel level is between 15-85 percent.

Important: Whenever the ignition is turned ON, ignition positive voltage is supplied to the HO2S heaters. After verifying the enable criteria, turn OFF the ignition for approximately 5 minutes to allow the sensors to cool before continuing with the test. Once the engine is started, DO NOT turn the engine OFF for the remaining portion of the set procedure.

Turn OFF all of the accessories,
Set the vehicle parking brake.
Verify the transmission is in Park for automatic transmissions and Neutral for manual transmissions.
Start the engine and allow the engine to idle for 2 minutes.

Acceleration at part throttle to (55 mph) with this speed maintained until the engine reaches operating temperature. This may be up to 8 minutes depending on the start up coolant temperature.
Continued operation under these conditions for an additional 6 minutes.

Acceleration at part throttle to (45-55 mph) with this speed maintained for 2 minutes.
Deceleration to (0 mph).
Engine idling for 2 minutes while the following criteria is maintained:
The service brake is depressed.
The automatic transmission is in drive.
The manual transmission is in neutral with the clutch pedal depressed

Thanks Pete

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