Hello everyone, I'm having issues with my Jaguar X-type that was at a mechanic for the installation of a flexfuel conversion kit to run with ethanol. The conversion kit is now deconnected and I run with petrol but the problem that appeard at this mechanic is still there.

The engine more or less misfires when I accelerate hard and shakes significantly. OBD read indicates misfires on bank 1 (cylinders 1, 3 and 5) and indicates that it could damage the catalytic converter.
I already changed spark plug and switched coils.I suspected an air leak on the intake because some brass inserts have been torn but I Fixed and intake gaskets are new and clean.
I noticed that when disconnecting the upper O2 sensor on bank 1 the engine run a little better, so i changed this sensor without improving the situation.

I dead a reading of Short Term Fuel Trims with OBD : bank 1 is at -25% and bank 2 is at 25%. Something weard about it : the value goes from 25 to 0 approximately every 10 seconds or when I accelerate hard. The engine behavior change synchronously with this variation (run good when STFT is 0%) and engine light also lights up synchronously.

Any idea ? Thanks.

Fred

 

Had similar symptons and after goung through everything from plugs, coils injectors, air leaks it was the front catalytic converter. I found out by removing the upper O2 sensor abd looking inside with a camera, it had totally melted inside and was restricting the exhaust flow. Got a new catalyser from Magnaflow.

 

Thanks for your answer. I will borrow a friend's endoscope camera and look inside the catalytic converters.
Yesterday I did several tests like spraying brake cleaner all arround the intake manifold manifold, clean spark plugs (the ones of bank 1 was dark and full of soot) and switch coils, O2 upstream sensors, camshaft position sensors, control valves on the manifold and finaly runing without O2 sensors.

 

I forgot to ask you : how did you knew the cat was broken ? Have you notice check engine light or default code ?

 

I spent many hours chasing this problem as I had warning lights and codes. The back 3 cylinders ran perfectly with no codes, but the front 3 cylinders were out of control! The car ran fine up to about 2500rpm and would cruise fine on the motorway, but as soon as I asked more from the engine going up a hill or accelerating then the engine light flashed and the power cut off at 3000rpm making it undriveable.
The ECU was cutting the fuel on these front cylinders as it thought it was overfueling, so I replaced injectors,fuelrail, O2 sensors, plugs and coils and checked for air leaks. But nothing made it go any better, I did many miles with my Code reader plugged in recording fuel trims and all data related to combustion.
What threw me was it would run fine up to a certain rpm so I thought the catalyser was ok, eventually I looked inside with an endoscope and saw the matrix had collapsed, this caused the exhaust at higher revs to back up and the O2 sensor read that there was little or no oxygen present so interpreted it as over fueling and told the ECU to cut the fuel on these cylinders which then made the engine run rough and threw lean codes.
I replaced the cat and its run perfectly for 6 months now, so the collapsed cat was restricting exhaust flow and the codes were leading me in the wrong direction, so what I learned is the codes don’t always relate to what is actually happening. Hope this helps.

 

I bet the mechanic totally rewrote your fuel maps and the system is just pumping out programmed lean and rich conditions. It’s way too coincidental that when you went in for a flex fuel conversion, which would involve remapping your fuel Maps in your ECM that that you’re getting weird fuel mixture readings now.

what was involved with the flex fuel conversion? I didn’t realize they had kids to do this but I guess they do. what do you know about it?

do you have access to SDD? Because you can go in there and look at what you are sub feedback, routines, and field Mabs look like and clear them out and see if that helps. Or reload your engine control module with its original program by configuring it as a new module, it has to be related to what your mechanic did so find out what he did. Did he take stuff apart? He must’ve changed the programming for the fuel map tables. What did he do to put it back to the original condition?

 

I did E85 conversion on my 2003 2,5 AWD myself, with this kit eFlexFuel E85 flex fuel conversion kits - eFlexFuel Technology more than a year ago.
It has a wiring harness, that connects between injectors and ECU, a control unit and a sensor that is situated in the fuel line which determines the level of ethanol in fuel.
There's no need for ECU remapping, and conversion can later be removed alltogether, bringing the car back to stock, in one so desires.
After installation, I had similar symptoms, misfiring and poor performance. I tried to locate a intake leak, that I suspected caused it, checked upper intake seals with brake cleaner, IMT o-rings etc. all 'big three' usual suspects, but could not find it
Reason was that, when I installed the wiring harness, i removed the fuel rail, and few injectors were disconnected from the lower intake manifold during assembly, O-ring on the injectors were not seated correctly, or were brittle, and leaked.
Lesson learned, replaced all injector o-rings (kits available on ebay or Rockauto etc.) and while I was there, replaced all injector filters as well.
Finally, new upper and lower intake seals, and she's been purring happily ever since.

You migt want to check your fuel filter too, since ethanol cleans up any 'gunk' you might have in your gas tank and fuel lines.
And no, I'm not in any way connected to that company that sells those conversion kits

 

You're right about the conversion kit. There is no modification of the ECU mapping.

I have access to SDD 138 but it's very complicated to use on my opinion and I'm not able to do anything with it. Maybe I should take time to learn to use it.

I ordered a o-rings kit for the injectors and wait the delivery.

I already changed fuel filter. I checked fuel pressure with OBD and it's very good. Anyway, I think that a bad fuel pressure would affect both banks of cylinders in the same way.

I will check the catalytic converters tonight with an endoscopic camera.

 

Guys, like we say here in France : "Mass has been said".

Bank 2 :


Bank 1 :


The quality of the photo is poor but there is no doubt about the diagnosis.

​​​​​

 

Thats how mine looked, cats aren’t available from Jaguar anymore and there are no aftermarket cats here in Norway so I found that Magnaflow in the US made one so I had it sent to my parents in the UK and then collected it on a trip over to avoid being clobbered by Norwegian customs. It took a few hours to replace as you have to drop the radiatir support beam and radiator a few inches to get the fan shroud and fans off. Then you have room to get a spanner on the three nuts holding the cat to the manifold. A tip is fit the short pipe from the bottom of the cat to the Y piece to the cat first then fit the cat to the manifold as you can’t fit it afterwards, don’t ask me how I know! You need the car up on a lift to make life easy, I used the big forklift truck where I work by just driving up onto the wide flat forks we use for lifting boats.
The Magnaflow part number is 52014MF and it comes with gasket and new nuts, they list it as for the 3 liter engine but it fitted my 2.5 no problem as the original Jag part number is the same for both engines.

 

Unfortunately, it's the rear catalytic converter that colapsed. It's available at SNG for more that 1600€ or Magnaflow sell it for 800 dollars (and Ebay for 150€, any opinion about that ?). If I am right, I have to get the engine out of the car.to change it...

 

I have read that it can be got out if you remove the manifold as well, fiddely to get to but saves a lot of work.