I know I'm not the first to deal with this and I have read several threads here on the matter but I still have no idea how to get past this. I failed a smog test back in February and am now my tags are three months past due and I'm open to any suggestions.
I did have a P0420 code some time back before the inspection. The code had cleared but oxygen monitor sensor won't reset. A scan shows no codes and 1500 miles and 200+ drive cycles since the last code. The EVAP system is also not reset but I have confirmed that the DMV will let that one slide.
I have contacted the state about a smog referee solution but was told this situation does not qualify.
I have read the drive cycles required for the oxygen sensors and made numerous attempts to put the car through them and am pretty sure I've covered them all at least once. I did replace the downstream O2 sensor on the right side and have done the drive cycles since then. I am not crazy about guessing if replacing a particular part will solve the problem but am open to suggestions
I have been to three local independent Jag repair shops and each has been sympathetic but basically told me there was nothing they could do and only driving will reset it. That was fine as the deadline approached but now three months later I am desperate for more ideas.
Has anyone else dealt with this and ultimately solved it?

 

My problem was a little different from yours. I had a fault due to starting the engine on my 2005 XJR without the MAF being plugged in.

I went thru about 200 miles of driving and no luck in getting things reset. Very frustrating.

However when I started driving in a lower gear and manually switching between gears, never in overdrive, it reset in less than 20 miles.

A long shot but I thought I would share my experience.

 

My comprehensive components, & oxygen sensor on mine, for nearly a thousand miles.
No light, just checked things before the emission test.
No idea why car did this, all was well for over a year now.
Passed the emissions test last time, no light since, or battery disconnected.

 

I decided to do another scan this morning and to my mild surprise, the only sensor not ready was the EVAP system. I went directly to get the smog test and passed.
Three things of note have happened since my first post.
1 - Used a tank of gas with an additive called Guaranteed To Pass. I wasn't optimistic but figured it was worth a try at $12.
2 - Tried the manual shifting as suggested by jackra_1. It's easy to do and can be done during normal driving.
3 - My wife borrowed the car yesterday and did a 50 mile round trip to work and back. A different foot made a difference?

Impossible to tell if any of these or a combination of them did the trick but I'm just happy that it's done now. Thanks to jackra_1 for the suggestion.

 

I like a happy ending!

 

I am having almost identical symptoms. Actually forget "almost" - they are identical. I have a NA 4.2 in a 2007 Vanden Plas. It has 102k miles, I replaced the plugs right at 100k with the pricier OEM ones: NGK IFR5N10 (7866) vs. the BKR5EIX-11 (5464) - I figure if I am taking the time to do them, AND they have a 100k lifespan, why not get Jaguar's choice for plugs. I have never changes any O2 sensors in this car. My Short Term and Long Term fuel trims are... well, I am a bit baffled at reading them, so I can't say if they are out of spec or not. Any major out of range I should look for?

About 6-8 weeks ago I ran the battery down leaving ignition on overnight. Really dumb move, but at least it's not like the points days where you could fry the contacts doing stuff like that. The battery is decent and about 2 years old. For Evap, I have been trying to keep the tank 25%-85% as advised.

I will of course try the same things that worked for thegreenjaguar, though I feel like it's not a very scientific approach.

1. Use a tank of gas with the additive: Guaranteed To Pass. - I'm familiar with it, and while it could clean the O2 sensors up a bit, it's not likely to do much else for me. I love their "guarantee" - You need to a) Get car inspected (and fail) b) use the product, c) reinspect, fail again. d) Spend whatever is required to REALLY fix the issue. e)Get the car inspected YET AGAIN. f,g,h,etc.) Rinse and repeat until it passes. q)Send ALL this documentation to them. r) Get a check back for $14 or whatever you paid. What percentage of people buying the product go through all these motions to get their purchase price returned? - BUT; I am still okay with spending 15 or 20 bucks if it gets me where I need to be.

2. The manual shifting is interesting. I already do some one a regular basis, but I would like more detail. When I manually shift the ZF 6HP, but dod so generally as a downshift to decelerate, saving brakes (and preventing the brake lights from illuminating and making me look bad in stop and roll traffic, to people who make a sport out of anticipating the "flow" of speed. Hey, at least it makes the commute more interesting than watching paint dry. 3. Ok, so I am NOT going to hand over the car to my wife. At least not until the other two approaches have been attempted and have failed. Yes, I trust her. Yes she is a good, safe driver. Doesn't matter. I don't LIKE people driving may Jag. NOT THE GUY AT THE TIRE PLACE - NOT THE GUY FOR STATE INSPECTION... NOT... well, that's the only people I have let in there. What can I say.. I've been burned before. I'm the really obnoxious guy who stand at the door of the bay that my car is in, GLARING at anyone who gets close to the car. I'm not real popular at the local garages. I can't imagine why...

 

I did random shifting while otherwise driving normally.

I would down shift from 4th to third without changing speed and down to 2nd without changing speed and back up all while diving back roads at about 50-60 mph.

I did not use overdrive at all.

Prior to doing this I simply cruised on a variety of roads at speeds ranging from 30 mph to 80 mph and could not get the desired result.

 

The approach is certainly not scientific but I was at a point where I'd try almost anything. My method was manually shifting up through all gears and did not manually downshifting. I would let it slow down to a stop (using brakes) in whatever high gear I got to and then shift back to 2nd and start over. Since there is a good amount of voodoo going on here I would suggest trying both approaches.

Blaireware, How many miles have you put on yours trying to get it to reset? I ended up with over 1500 although there's no way of telling which combination of those were the critical ones that did the trick.

 

Seems the older earlier models like my 04 take what seems forever to clear.
The 07 is much faster to pass all 8 of the emission tests.

 

Thanks Jackr_1, Wingrider and thegreenjaguar for suggestions. As I mentioned, I downshift on a somewhat regular basis, for several reasons, but I haven't used manual to hold gears while driving. Thats the next move I will take. Note: Not everyone realizes that 2nd through 6th are all available. I saw a video that explained that you have "2 through 5" but no way to control 5th to 6th gear. Not true. Even though the J-gate gets panned by a lot of folks, and it's not a slick as the "Tiptronic" (Porsche's system) types used in VW/Porsche/Mercedes Benz, it was decent method of controlling gears, and offered more gear control than the "Up-down" tiptronic shifter. With the up/down, one gear at a time, you needed a dashboard indicator to know WHICH GEAR you were in, specifically.

5th/6th is a horizontal motion, and the others are vertical. Takes about 2 uses to become second nature. That's the shift I perform the most often. When rolling downhill, creeping up on the car in front, I just bump the shifter left and it drops road speed about 5 mph without touching the brake.

I am grabbing either "Guaranteed to pass" or another "Cata-clean" product that claims to clean the O2 Sensor tips. My understanding is that certain conditions, such as too many "outside of range" results and certain conditions can make the system toss it's results are start monitoring over so I need to try and get usable data to complete the O2 test. The Evap could be simple, or could be difficult. It is NOT likely to be a fuel cap seal. I geta loud, sharp "CLICK" under the hood of BOTH X350 cars I've had. I though perhaps it was the purge valve for the carbon canister, but someone familiar with it told me it was unlikely to be making a sharp loud click. It would be nice to get more specific detail on the evaporative data it's looking for.

I will keep you posted on my progress or lack of it. Thanks guys!

P.S> thegreenjaguar: I MUST ask: so... what color is your XJ? (colour?)

 

I get a loud sharp click under the hood of my car regularly ever since I bought it. I have always thought it to be something to do with the AC compressor. Originally thought it was a clutch but someone stated they are clutch-less. Nothing untoward has ever happened and it cannot be heard inside the car.

 

No big surprise here but it's Jaguar Racing Green. It started with a quote from the movie Tin Men which led me to use the name thebluecaddy on a site dedicated to those cars. That was followed by theredtiger, thebluemini when I had one of those and eventually my screen name here. Not super creative but logical, at least.

Back to the sensor reset issue, have you done a decent length trip on it yet? Looking back at my journey, I did do runs of ten miles or a little more each way trying to do the drive cycles but it may have been the 25 miler each way my wife drove that did the trick. I seem to recall reading on another thread on the topic that someone took his car out for an extended day trip including driving mountain roads and having success.

 

thegreenjaguar: With the context, the member name makes perfect sense. As far as the longer trips being the potential solution to getting complete O2 Sensor data there's only two words that I can say... "ROAD TRIP!"


Thanks Jackra_1 - It's helpful to know that not only my two cars did this. I have not had any related issues that I can tell either. The AC Compressor is not only clutchless but "multi-displacement" This short animation demonstrates what is a very cool design:





They are quiet, and known to be bulletproof. I do get a soft "buzz/whine" when running the AC - I suspect its either a fan bearing or an auxiliary pump, and both cars made this sound as well. Stuff like that actually helps me realize it's probably a design weakness, but at least its common and not unique to my car.



I LOVE that this VDP has the 4 Zone AC with an additional evaporator and fans inside the center console for rear passengers, along with digital auto-temp for each rear passenger. I DIDN'T love opening the center armrest to find... enough room for a pack of gum -the 5-stick variety - the value pack would never make in there. It's comical and makes you wonder why they bothered with a hinge on the armrest. Worse, I have the pop up cup-holder, similar to the X308 ones that broke if you so much put an extra ounce of force on them. I have proactively been hunting spares and from over a year's research I can confidently say if it breaks I am screwed.

 

There are far worse ways to try to fix the issue.