06 STR O2 Sensor Not Ready
 

Hello everyone. I am having some trouble trying to get my 06 STR to pass smog. I have recently done some work such as new injectors, cats, ac compressor, etc. This required pulling off the battery which reset all the sensors. I have done a wide range of driving cycles on the car with over 500 miles. But I am still getting O2 sensors as not ready. All other tests are completed and no check engine codes. The car drives nice and gets the correct mpg. Can this ongoing pending mean bad o2 sensors? Any advice would be highly appreciated.

-Nick

Does your scanner show both banks operating in closed loop? I'd think you'd get some kind of code if stuck too long in open mode, but who knows.

You could look at fuel trims (and sensors) in the hope of some hints.

I have the same car and had the same truoble....i finally went out in the countryside and did some full throttle accelerations and some near 100mph stints and the o2 sensors set....maybe my cats are marginal and the heat and full fueling helped....all i know is it works

​​​​​​ I dont have to get smogged but I still can’t get all my sensors Ready.

Any performance parts, such as the new cats and injectors? Or is everything OEM or equivalent?

Definitely check your scanner as stated.
It should have the clues.

but also there are a couple of unusual requirements for the S- type
to complete its monitors checks .
One I always have to do to get the last monitor is a long deceleration from above 2500 RPM.
can’t remember the stated speed range.
something like - 100kph to 30kph
also it must have above half a tank of fuel.

and watch out for non genuine sensors . It’s Russian Roulette.


although, On mine I have no cats , and down stream shortie o2 45*Extenders.
and have no trouble completing my O2 sensor checks.
They are my quickest to pass .

Hey thanks for all the replies. As for aftermarket parts. I recently had the injectors rebuilt and tested professionally. I also got magnaflow CA cats that are verified for my engine number and state laws. Only other thing I could think of are oxygen sensors. I just ordered 4 new Denso oxygen sensors in hopes that will speed up the readiness sensors. Will get back with updates.

That might do it.....the front o2 sensors are very touchy and switch extremely fast....what the pcm is looking for is a constant reading for a certain parameter....i also replaced my o2 sensors and had the no set results until i did my made up drive cycle that i posted...after you change them out, try my version if you can along with datsports decel cycle and i bet they will set

The fronts on this era don't "switch" as they are linear (aka wideband). They do REACT very quickly, if that's what you meant, allowing fast accurate fuelling.

Exactly what i meant...thanks Jagv8...they are tricky to interpret sometimes as they change so quickly

Tricky in what way? You just use an OBD tool and it should tell you what the sensor is reporting. (Scrap any tool that doesn't.)

Hey again everyone. I have put the new O2 sensors on yesterday and drove about 70 miles or so. Still no luck. Currently have around 300 miles on the drive cycle since the last ECU reset. Any other ideas? or is this just a matter of driving it a lot throughout the next few days? I want this smogged and over with.

Another update. After driving the car with the new O2 sensors. I am getting pending lean codes again. These came on pending, then went away, then came back on pending. I have been fighting these lean codes on and off for years now. I brought the car to a Jag specialist shop about a year back and they told me they think it was injectors. So after a lot of work, I was able to take the injectors out and have them rebuilt. I thought the lean codes were gone, but sadly they are back (pending). Any advice would be highly appreciated. I've done the smoke test for vacuum leaks, the 44k fuel cleaner route, replaced fuel filter. After the injectors, I have ran out of ideas. It's a long shot, but do these ECUs ever go bad?

Below are some screenshots from obd2.

https://imgur.com/a/idJffCm

The PCM is the very last suspect, especially as it's making sense.

What are the fuel trims now? What do they do in the usual tests?

Do the various sensors have plausible values?

Lots of confusing data in that thing you posted, no idea what use it is to you.

Last I checked the LTFT were at 15. Then dropped to 8. Then lower. But back at 12ish. They kinda are all over the place. As for the screenshots. I’m not looking at all that info. Just thought I’d share for people that may know more about obd2 data.

Only positive I see is before the new o2 sensors, I drove the car 500 plus miles and no pending lean codes. At least now something is happening. I’d rather get a code and completed sensor vs driving 100s of miles with no answers. Any info is always highly appreciated.

Just follow the frequent advice on fuel trims, don't make it complicated yet.

What codes are you getting? P0171 and P0174 together? That would indicated a lean condition on both banks. Or are you getting a code for just one side?

If just one side, I'd suspect your new O2 sensors. As these wideband sensors are not cheap, you could swap them side to side and see if the problem follows.

One important thing to remember with O2 sensors: We mere mortals have no conclusive way to know if they are accurate. AFAIK, the only practical method is to use an old-fashioned exhaust sniffer like used in a shop or emissions testing station. Instead, we slap in new sensors, assume (Danger! Danger!) they are accurate because they are new, and off we go. This is usually just fine, but there's always that exception...

The bulk of fuel scheduling is based on the readings from the O2 sensors. If way out of tolerance, you'd get some kind of code faulting the sensors. But the more typical situation is a sensor hovering near the edge of the range of specified accuracy. In other words, not so bad as to throw an O2 sensor code right away, but just enough to maybe throw off some other calculations. On a related note, computers are really smart and really stupid, all at the same time. They can only respond the way they are programmed. So if you've got a borderline inaccurate O2 sensor, it may be telling the computer to provide more fuel than is actually required. Meanwhile, the computer looks at multiple input all at once, such as RPM, throttle position, load, air flow, etc. If the calculated fuel flow exceeds what is normal for those conditions, it blindly interprets this as a vacuum leak when perhaps a marginal O2 sensor is the root cause.

Since your codes are pending, that would point to a condition right on the edge of setting a fault, teetering back and forth. And since this has only happened with the new O2 sensors, that would point to a problem with one or more of them. So if only on one bank, swap side to side. If on both banks, I'd reinstall the old ones and see if that clears it up.

Back to your original issue of the O2 monitors not setting, I may have found your answer. See page 5 here for the official procedure. Not exactly normal driving procedure, especially the requirement to idle for 11 minutes. To do this procedure, you may have to find some deserted location, such as the parking lot for the headquarters of the Nancy Pelosi Appreciation Society :


http://www.jagrepair.com/images/Auto..._OBD_II_R2.pdf


HEATED OXYGEN SENSORS MONITOR DRIVE CYCLE Upstream (Universal) oxygen sensors:
1) Engine OFF; cooling fans inoperative > 20 seconds.
2) Start engine and bring to normal operating temperature > 82 °C (180 °F).
3) Drive the vehicle between 3000 – 4000 rpm in 3rd gear at a steady speed. Lift foot completely off accelerator and coast to a stop within 30 seconds. Do not touch accelerator pedal for 4 seconds after coming to a stop.
4) Repeat step 3.
5) Idle engine for 11 minutes.
6) Say nice things about the guy who found this buried in an official Jaguar document.

Downstream oxygen sensors:
1) Start engine and bring to normal operating temperature > 82 °C (180 °F).
2) Drive the vehicle steadily between 48 – 97 km/h (30 – 60 mph) for 10 minutes.
3) Drive the vehicle above 3000 rpm in 3rd gear at a steady speed. Lift foot completely off accelerator and coast for 30 seconds.

Oxygen sensor heaters:
1) Start engine and bring to normal operating temperature > 82 °C (180 °F).
2) Idle engine for 3 minutes.

Wow thank you for the detailed response! I will try the specific drive cycle and see what happens. Let's hope for the best.

If you're that close to codes or getting codes then don't be surprised if the drive cycle does not help with fixing the fault. Focus on the codes and their causes.