o2 sensor not ready after performing drive cycle requirements.

[rodneydangerfield]

I have gotten all the readiness monitors functioning except the O2S monitor.

The drive cycle I did was:

- idle for 5 min
- drive over 25 for 2 minutes
- idle for 30 seconds
- drive to 30-40
- repeat last two five times

It got the EVAP monitor ready but the O2 monitor is still not ready.

Really would appreciate some advice.

 

[chopperman1]

Keep driving it. Drive cycles are not an exact science, more a general guideline.

 

[GTyankee]

is your fuel tank at least 1/2 full?

How To Perform A Basic Drive Cycle​

Performing a basic drive cycle involves the following steps:

• Start the engine: Ensure the engine is at its normal operating temperature, which can be achieved by idling it for five minutes.
• Begin the drive cycle: Begin the drive cycle by driving the vehicle at a moderate speed, usually around 40 mph, for a few minutes to warm up the engine and transmission.
• Drive at various speeds: Drive at a steady speed of 50-55 mph for 10-15 minutes, at 40-45 mph for 10-15 minutes, at 30-35 mph for 10-15 minutes, then accelerate to 60 mph and then decelerate to 20 mph for 2-3 times. Drive at a steady speed of 55 mph for 5-10 minutes. Drive in stop-and-go traffic for 5-10 minutes.
• Accelerate: Accelerate the vehicle to its maximum speed, usually around 60 mph, and maintain this speed for 30-60 seconds.
• Decelerate: Decelerate the vehicle back to its original starting speed by pressing the brakes firmly.
• Cruise: Cruise at a constant speed for several minutes, usually around 40 mph, to allow the vehicle's systems to stabilize.
• Come to a stop: Let the vehicle normally decelerate after cruising. Let the engine idle for a minute and shut it off. Come to a stop.
• Repeat the cycle: Repeat the above steps several times to complete the basic drive cycle.
• Check the diagnostic codes: After the basic drive cycle is completed, check the vehicle's diagnostic codes to identify any issues with the vehicle's systems.

 

[rodneydangerfield]

Thanks chopperman1 and GTYankee, I will keep driving it and will try that drive cycle. The gas tank is more than half full.

 

[Rado]

Very interesting
! I have no idea what a Drive Cycle is lol
I will look it up ,,
I am not mechanic but love learning different things

 

[Sherman Bird]

I have gotten all the readiness monitors functioning except the O2S monitor.

The drive cycle I did was:

- idle for 5 min
- drive over 25 for 2 minutes
- idle for 30 seconds
- drive to 30-40
- repeat last two five times

It got the EVAP monitor ready but the O2 monitor is still not ready.

Really would appreciate some advice.

You're wasting your time if the ambient air temperature where you live is under 41 degrees F at the time of your drive cycle attempts. The fuel tank should ideally be at 50%.
I've learned that the O2 sensor monitors are fickle.

 

[GTyankee]

@Rado
Maine's definition of Drive Cycles

Drive Cycle — Check Engine

www.checkengine.me

 

[Mister Luck]

I have gotten all the readiness monitors functioning except the O2S monitor.

The drive cycle I did was:

- idle for 5 min
- drive over 25 for 2 minutes
- idle for 30 seconds
- drive to 30-40
- repeat last two five times

It got the EVAP monitor ready but the O2 monitor is still not ready.

Really would appreciate some advice.

The o2 is the replacement for the what was once called the choke adjustment which use to be a cable that ran from the dash of the vehicle to the carburetor.
Similar to what is on a lawnmower or similar gas powered garden tool.

The operating system for the o2 was invented because most drivers didn’t understand its function and would use it in any instance where the combustion process or performance of their engine wasn’t acting as anticipated.

For the modern o2 to work the operating temperature of your engine needs to meet it’s optimum temperature.


Not just what is typically referred to or required as normal, since different criteria has been introduced and concluded to meet the best temperature combination for complete fuel vapor consumption.


Before the o2 can control the emissions and offer (think automatic choke) electronic feed back on fuel consumption the coolant temperature needs to reach / (read) the preprogrammed temperature which is controlled primarily by the coolant thermostat opening and staying open..


where as your driving habits or skills are aided or compromised by speed or acceleration of the vehicle and or ambient air temperature and or atmospheric pressure and or altitude.

 

[pacofortacos]

The o2 is the replacement for the what was once called the choke adjustment which use to be a cable that ran from the dash of the vehicle to the carburetor.
Similar to what is on a lawnmower or similar gas powered garden tool.

The operating system for the o2 was invented because most drivers didn’t understand its function and would use it in any instance where the combustion process or performance of their engine wasn’t acting as anticipated.

For the modern o2 to work the operating temperature of your engine needs to meet it’s optimum temperature.


Not just what is typically referred to or required as normal, since different criteria has been introduced and concluded to meet the best temperature combination for complete fuel vapor consumption.


Before the o2 can control the emissions and offer (think automatic choke) electronic feed back on fuel consumption the coolant temperature needs to reach / (read) the preprogrammed temperature which is controlled primarily by the coolant thermostat opening and staying open..


where as your driving habits or skills are aided or compromised by speed or acceleration of the vehicle and or ambient air temperature and or atmospheric pressure and or altitude.

Not a replacement for the choke - as it doesn't even come into play until the engine/sensor is warm.

If you were to compare it to something from the carbs from back in the day, it would probably be closer to the power valve/accelerator pump/metering rods.

For few years, they actually used an O2 sensor to operate a duty cycle solenoid in the carb - basically a variable jet.

But back to the OP's drive cycle, GTyankee's procedure will usually get the job done - ie. basically drive it normally for a few days.

 

[Rado]

@Rado
Maine's definition of Drive Cycles

Drive Cycle — Check Engine

www.checkengine.me

Thank you

 

[Sherman Bird]

Thank you

Yeah, well, the manufacturers all have different strategies. The one for 2011 year model Fords is VERY complex. It's akin to reading trig.

 

[Mister Luck]

Not a replacement for the choke - as it doesn't even come into play until the engine/sensor is warm.

If you were to compare it to something from the carbs from back in the day, it would probably be closer to the power valve/accelerator pump/metering rods.

For few years, they actually used an O2 sensor to operate a duty cycle solenoid in the carb - basically a variable jet.

But back to the OP's drive cycle, GTyankee's procedure will usually get the job done - ie. basically drive it normally for a few days.

Your half right (you're not even close) ..you ever drive a automobile with a choke ?


EDIT (for me personally)
It would have to be pre smog pump era..
but then those where retrofitted to most earlier cars after 1956..
I’m not afraid to admit it
I own socks that are older than you.

The link to the drive cycle is a generic instruction more likely to preformed on a dynamometer for emissions testing class.

Yes drive the vehicle for a few days and see if it clears. Otherwise why was the o2 replaced simply because it stopped working , then you’d have to ask yourself why did it stop working ?

 

[pacofortacos]

Your half right (you're not even close) ..you ever drive a automobile with a choke ?

View attachment 533050
EDIT (for me personally)
It would have to be pre smog pump era..
but then those where retrofitted to most earlier cars after 1956..
I’m not afraid to admit it
I own socks that are older than you.

The link to the drive cycle is a generic instruction more likely to preformed on a dynamometer for emissions testing class.

Yes drive the vehicle for a few days and see if it clears. Otherwise why was the o2 replaced simply because it stopped working , then you’d have to ask yourself why did it stop working ?

LOL trust me, I have forgotten more about cars than most people know.

The O2 circuit is in open loop until both the engine and the sensor reach operation temperature, once those and other parameters are obtained then and ONLY then does the O2 circuit go into closed loop and provide feedback to the fuel system - prior to that time, it's the computer programming determining the fuel mixture.
If you want I can show you all of this on a Snap on scanner.

A choke only operates when the engine is cold and is fully open within a minute or so of starting the engine - at that point, the choke is a non player in the fuel management.

The O2 and choke operate at opposite engine temps.

Both my boat and excavator use a choke, one auto, one manual - so I am well aware how a choke operates

 

[Sherman Bird]

LOL trust me, I have forgotten more about cars than most people know.

The O2 circuit is in open loop until both the engine and the sensor reach operation temperature, once those and other parameters are obtained then and ONLY then does the O2 circuit go into closed loop and provide feedback to the fuel system - prior to that time, it's the computer programming determining the fuel mixture.
If you want I can show you all of this on a Snap on scanner.

A choke only operates when the engine is cold and is fully open within a minute or so of starting the engine - at that point, the choke is a non player in the fuel management.

The O2 and choke operate at opposite engine temps.

Both my boat and excavator use a choke, one auto, one manual - so I am well aware how a choke operates

I'm all choked up!!

 

[GTyankee]

I have an older SEARS Generator that has a choke.
It is so old it may have real gasoline in the tank.

 

[Mister Luck]

LOL trust me, I have forgotten more about cars than most people know.

The O2 circuit is in open loop until both the engine and the sensor reach operation temperature, once those and other parameters are obtained then and ONLY then does the O2 circuit go into closed loop and provide feedback to the fuel system - prior to that time, it's the computer programming determining the fuel mixture.
If you want I can show you all of this on a Snap on scanner.

A choke only operates when the engine is cold and is fully open within a minute or so of starting the engine - at that point, the choke is a non player in the fuel management.

The O2 and choke operate at opposite engine temps.

Both my boat and excavator use a choke, one auto, one manual - so I am well aware how a choke operates

I guess it helps to know why the o2 was invented and you’re right it is for fuel management but prior to the o2 different inventions and methods where used to regulate air fuel mixture before the advent of the electronic fuel injector the choke was the most widely used in early production vehicles… but like you mention … maybe that’s a part you forgot.

 

[pacofortacos]

How does the choke regulate fuel management once the engine is at operating temperature?

Enlighten us, please.

Early production vehicles??? LOL

 

[Sherman Bird]

I guess it helps to know why the o2 was invented and you’re right it is for fuel management but prior to the o2 different inventions and methods where used to regulate air fuel mixture before the advent of the electronic fuel injector the choke was the most widely used in early production vehicles… but like you mention … maybe that’s a part you forgot.

I remember the first O2 sensors showing up on BMW's of the late 70's. Soon, Asian cars began to use them. Nissan introduced the first choke-free, electronic feedback carburetor and Ford had the variable venturi unit on the 302 and 351's.

In 1979, GM introduced the CCC, or C3 system (Computer controlled carburetor). The crude fuel management in those days caused so many problems that many folks ripped those systems from their cars and installed old fashioned distributors and carburetors. By 1981, all 50 states required the C3 systems, and all the makers had outer space bizarre feedback systems which almost no one understood; including factory dealer techs in many instances.

The downside then, as now, was and is how basics are so often overlooked in diagnosing problems. Everyone wants to blame a computer because it does EXACTLY what it was programmed to do.

I'm currently working on a 27 year old E-150 van with the 302 engine; the first year of OBD2.... 1996 year model. 130,900 miles on the odometer.

It has been to 4 other repair facilities over the past 2+ years and nobody could get it running! I have it running like new, albeit with some DTC's which I'm sorting out. All I did was start with basics and went from there.

Industry wide today, Oxygen sensors have been replaced by wide band air/fuel ratio sensors in many cases as of late, which gives the computer a much wider margin of air, fuel, and correction control. But, that still doesn't change the basic principles on which an ICE (internal combustion engine) operates.

The technology is vastly different germane to strategy of computer controls today as opposed to as recently as 6 years ago. This makes helping a stumped fellow who is trying to fix his ride MUCH more difficult without having the vehicle present and hooked up to multiple diagnostic tools.

 

[Mister Luck]

How does the choke regulate fuel management once the engine is at operating temperature?

Enlighten us, please.

Early production vehicles??? LOL

I think registration in a legitimate college or university is in your future.
Maybe licensing through a state or local legislative branch would be worth your time. (Come back and ask me then)

 

[pacofortacos]

Since I worked in a Chrysler/Plymouth/Jeep dealership, I saw all of their versions.
Remember Lean Burn? Or the terrible Chrysler Imperial system?

Our factory Rep often got to drive pre-production vehicles, so we got to play and drive some of those rides
First EFI (mopar) that I worked on was in 1983, officially EFI wasn't introduced until 1984 but somehow there was a 1983 model that escaped and I worked on several times.
He brought in a 1984 Turbo Z and again the 88 Turbo II both pre-production vehicles. In the performance drought of the late 70's/early 80's, the 84 Turbo Z was a refreshing change - sure not a V8 but it was fun to drive

What's nice is that the 5.7 computer and fuel system really isn't that different from the 84 Turbo - sure it's more advanced but over all, the way the whole system works is almost identical.

The mopar single point and multi point EFI systems were several years ahead of what GM and Ford offered at the time.

I lucked out and had to work on an late 70's/early 80's VW mechanical fuel injection system It had some serious issues and we finally gave up on it, I want to think that it may have had the fuel contanimated with. Managed to get it to run, but it was never right and either had cold or hot running issues - good hot, not good cold - good cold, not good hot.