Wrinkly

Money

Still not able to find cause of P0420 code, despite all that has been done (as per above details in this topic). However the car has recently had, six of each, new Ignition Coils and Spark Plugs (all good manufacture, E.G. Denso) and Inlet gaskets were new ones of Jaguar origin. Is it possible that during re-fitting the Inlet Manifold, that a gasket has been pinched or not positioned correctly. The car is showing no signs of what is usually considered as typical Cat Converter in effective, E.G. Smell, low mpg. smoke, power loss etc. etc. Every time the code is read and reset it appears again in 18 -20 miles of use. Further advice would really be appreciated. Regards and Best Wishes, John

Sticky

Sunken

Destruction

finish

Humour

As in starting a car, especially an S Type, if battery is low.

Jim Have removed airbox as your suggestion, no obvious air leaks. I am assuming it is in order to lightly hear air passing along from the air cleaner when I have my ear on the delivery tube to the throttle body. Regards and Best Wishes , John.

Jim Thank you very much. I will attempt to look into this. Regards and Best Wishes , John

Have been doing a bit of searching around the internet and have found this entry on a USA Jaguar website, concerning P0420. It is suggesting that most of these codes P0420 generated are due to air intake via leaks, on usually plastic joints, is causing the problems. Leaks via Inlet Manifold etc, etc. and is shown on a video link in the posting. I would really be grateful if some of the well informed members of this Forum would be kind enough to view this link and video and give me there thoughts/opinions on the suggestion of too much air being read by the Lambda Sensors. As per my post above I just do not know where to go from here now that both Lambda have been replaced. https://www.jaguarforums.com/forum/x-type-x400-14/p0420-kept-coming-back-11218/page2/ Many thanks, Best Wishes and Regards, John.

Have posted before on this subject but am now at a loss as to what to do to correct. History of attempting to correct: Car was MOT`d April this year and had nothing needing attention and no points for attention. So, plainly must have had correct/acceptable emissions at that stage. Has done exactly 1845 miles since MOT. Car was serviced and I mean full service 1494 miles ago. 800 miles ago the Ignition Coils 6, Spark Plugs 6, Inlet Manifold Gaskets 6, were replaced because of a faulty Ignition Coil on Cylinder No: 3. Less than 300 miles ago Yellow Engine Management Light appeared. OBD11 code Reading P0420 Catalyst System Efficiency Below Threshold. Bank 1. (Left Bank when stood looking at engine from front of car. Correct I believe ?????). Upon advice the Lambda Sensor Upstream was replaced (Denso as OE.). after only 20 miles the same fault kicked in again. The Lambda Sensor Downstream (again Denso as OE) was then replaced. After18 miles today the same fault has appeared I.E P0420, as above. 1/ Would appreciate advice on what to do next to correct this fault. 2/ Has anyone any experience of using branded Catalyst Cleaners that are put in the fuel tank and run through the system. The advertising for them, as one would expect, is full of praise and "a cure all". Is it worth trying for the sake of £20. Will they cause any harm or damage. 3/ Do you believe I am really looking at the costly action of buying replacement Catalytic Converter/s which seem to be in the region of £155.00 each. 4/ Due to travel to Cornwall in two weeks and would like to correct this before the weekend away. 5/ Will it do any damage to run the car with this fault not corrected and the Yellow Management light continuing to show. In anticipation of receiving some advice on above questions I would thank you in advance for your time and efforts on this problem Best Wishes and Regards, John

Jim Thank you very much for the information. How simple things can be when you know how. Regards and Best Wishes, John

This is going to sound a very silly question I am sure, but I cannot resolve the issue. The 6 disc stack player on my 2005 S Type 2.5 V6 appears to be running at all times when the ignition is turned on. Even when I am using another screen than the Audio Screen, if I turn the wheel that controls the volume level the disc is playing. This concerns me a little as it suggests the CD`s are constantly being played. Am I being an idiot (careful !!!!!!!) and missing something, somewhere as I cannot seem to be able to turn the CD stack OFF. There surely is an on/off switch to prevent the stack system from continuously working. This old boy would appreciate an answer to the problem and can put up with a rude comment if it is needed, as my daughter often tells me I am a Dinosaur. Many thanks and Best Wishes, John.

hopefully

station

Hi I bought a low mileage (61,000 mls) 2005 S Type 2.5 V6 Petrol Auto in April this year. In fabulous almost pristine condition. A good service history, although not had a lot done to it other than regular servicing and had all MOT`s. It was MOT`d for me before collection with no defects noted or advisories given, (a clean sheet). In my opinion I feel it is able to be classed as low mileage for its age, I have had to do a couple things in the reasonably short time of owning the car and only completing some 1000 miles in my ownership. Insisted with my purchase that the gearbox oil and filter were changed as part of the deal and this was complied with. 1/ Have replaced all six plugs and ignition coils. The only fault was at No.3 cylinder only, but whilst manifold was off all six plus and coils and manifold gaskets were replaced. 2/ Am currently attempting to get to the bottom of a Code No: P0420, relating to Cat reading below expected level on Bank 1. Have replace Upstream Lambda and yellow warning came back. Am now about to fit a Downstream Lambda in the hope of curing the problem. Used genuine Denso on both Lambda`s as these are original Equipment by Jaguar. This is not a major issue to me as the cars themselves are what I consider to be the last of the traditional looking Jaguars and are an absolute delight to drive and own. I absolutely adore my S Type and would not change it for anything else. I was always a petrol head and even at almost 72 I still am. I adore classic looking cars, having owned such cars as Nissan 200`s, Nissan Skylines etc etc in my younger years, as well as a Mk2 Jaguar as a late teenager. I wanted for many years to go back to a Jaguar and did so in April this year. My personal advice and opinion, although not necessarily reflective of other respected persons on this or any other Forum, would be look for a service history and proof of mileage (like via continuous MOT`s, (if possible by the same test station) and buy what you consider is the best you can afford. I would add to that, all of the decent condition S Types now appear to be fetching good and increasing monetary values and never seem to be valued by age related prices, which of course one would not expect from what is undoubtedly an up and coming future classic. They have a terrific comfortable ride and I can achieve 25 - 26 mpg with mine. Loving it, so go do the same yourself and enjoy it. Good Luck and Best Wishes, John

Hi Joe The Upstream Denso Lambda Sensor having been fitted has thrown the same Fault Code again at 20 miles, I.E. P0420 Catalytic Converter Bank 1 showing imbalance. Have now ordered the Downstream Denso unit in the hope of that being the cure for the Code Fault. Just wanted to be sure of Bank 1: in my understanding it is the left bank as you stand in front of the car and look towards the engine (I.E. cylinders 1, 3 and 5). Thanks again and Best Wishes, John.

Joe Once again many thanks for your help and assistance. Regards and Best Wishes, John

Is it possible to see some phots please. Many thanks.

Joe I specifically purchased Denso due to your previous advice that they were OE and it was best to buy them. In fact not very much dearer than some unknown brands that can be obtained. Many thanks and Regards, John

Joe Many thanks for the warning you have given me, I know the laptop I purchased (2/Hand) has mention of DVD. BUT to be very honest your kind warning means very little to me. I am not computer technical very informed. The laptop I use in the house is running Windows 10 and I get along quite well using it, but if anything needs doing to anything my son in law always sorts it out. I have attached hereto the Ebay Link to the Laptop I have purchased. Would appreciate your taking a look at it and informing me of my fate with what I have purchased. https://www.ebay.co.uk/itm/265278849401 As for keeping the car battery charged, no problem as I have already invested in a new OTEK MS 7.0, heeding your previous warnings how the S Type can be heavy on battery power usage. Many thanks for yet again being a pool of knowledge and very helpful. Best Wishes and Regards, John

Joe Have purchase JLR/SDD diagnostics and a stand alone computer running Windows XP PRO 3 to run it on. Also as an update to previous problem with Code P0420 reading Imbalance on Bank 1 Cat System. Have hopefully cured this with a New Denso Upstream Sensor. Car has done 16 miles to far with no yellow engine warning light. "Not counting the chickens before they hatch" as when I have reset on previous occasions it has taken between 16 - 20 miles for the warning light to reappear. Best Wishes, John

Cop

Success .......... have found the below link where a free download can be made. Hope it might be of use to someone else as well. https://www.mediafire.com/file/x6nmqyme3c34bcc/IDS-SDD-JLR_Manual_02_02_12.pdf/file Best Wishes and Regards, John