So once again my jaguar is acting up... I wish I could say I'm surprised but I'd be lying. I own a 2005 3.0L Jaguar x-type and it's been misfiring pretty badly. when the cars under load like climbing a hill at highway speeds the engine light with flash. I pulled the codes and I got a P0300,P1314, and a P13116 code. This car has had the engine light on since I bought it for what I believe is an O2 sensor issue because it shows codes P0420 and P0430 which I've cleared multiple times but they always seem to come back while driving on the highway. I'm wondering if the misfiring could also be from the O2 sensor and just curious what others think about this. Thanks in advance!

really starting to think I should sell Jenny the Jaguar and but something a little more reliable.

-Kolbe

 

First thing to look at is spark plugs, when were they last changed? It might also be a coil, but plugs are the first thing I would look at.

If you have an O2 sensor light it indicates a problem, so clearing the code doesn't do anything if the underlying problem is not addressed. If it is running lean for example, that can cause a misfire under load. If the O2 sensors are original, I'd start by changing them as a matter of course. I like the NTK or Denso brands, they are quality parts.

I get my parts at RockAuto.com, shipping to Canada is quite reasonable, and usually the total cost is quite a bit less than buying locally. Note that to change the rear sparkplugs you do need to remove the intake manifold, as is common with many V6 engines, not just Jaguar. The gaskets can be reused, so you can take the manifold off, change plugs and put it back together.

 

P0420 and P0430 on your X-type means that the computer sees something wrong with your oxygen sensor readings. P0420 is for bank 1 which is the bank towards the back of the car and P0430 is bank two which is the much easier bank at the front of the car.

The code p1314means that the catalytic converter is under a lot of stress and is burning too hot.

The code p1316 means misfire affecting catalytic converter with emissions outside of accepted parameters.

The P0300 means that the computer sees that the engine is misfiring. For an engine to properly fire, it needs the following: Fuel: the fuel pump pumping the right pressure at the rail through the fuel filter and the injector injecting the right amount of fuel.

If you had a P030X (where x is a number, i.e. 1, 2, 3...) the ending number tells you the misfire is cylinder #.

Btw, if your eml is flashing you are doing damage to your cats which can occur EXTREMELY quickly, like in a few blocks.

 

Thanks for the advice everyone! as long as I baby it the engine light doesn't flash it only flashes and misfires under heavy load so I'll just take it easy on her for now. I ordered both new oxygen sensors this morning and I'll install them and some new spark plugs once they arrive to see if that changes anything. I'll keep you guys updated thanks for the feedback!

 

Sadly, clearing codes like that is mainly a way to cause damage. You need to fix the fault(s) to avoid what may well be very costly damage which could have been avoided.

 

does anyone know which O2 sensors I should change or anyway for me to diagnose them? I didn't realise that there were 4 and I'd rather not replace all four if I don't have to. I was hoping it's just the the ones before the cats but I'm not sure...

 

That's why I started this thread... I wanna fix the faults ... I'm gearing up to sell her and don't want the next owner to have any headaches. Probably shouldn't have avoided the O2 sensor faults for as long as I did but I'm a high school kid with high-schooler money and didn't want to fork out the cash to have it done by a mechanic ... now that it's finally warming up in Alberta I can fix the issues without getting frostbite.

 

As far as the o2 sensors goes if your going to replace any then only replace the top two and not the lower ones. Faster reading and switching rates of the top new ones and the slower ( old ) bottom two sometimes will fool the computer that yours cats are working fine. Not always but allot of times. Having the p300 code is a random misfire for all cylinders so even tho the spark plugs is a great place to start you should also be looking at the fuel pump pressure at those loaded times and also checking for vacuum leaks. Could be something even as simple as needing the fuel filter changed. Lack of fuel also gives random misfire

 

Thanks for the feedback when you say replace the top two do you mean the ones labelled 1 and 4 on the diagram or the ones labelled 1 and 3? and I had hoped it was a vaccum leak but I've already fixed a couple leaks and haven't found any others since. The fuel filter is also new I replaced that when I bought the car and the pump is slowly going unfortunately. The car still drives pretty well it just won't start if I let the tank get to close to empty but I almost always fill it up at half a tank. Image of sensors: https://www.jaguarforums.com/forum/a...bda-jaguar.jpg

 

Yes 1&3 but however if you already know that your pump is on it’s way out then check your fuel pressure while driving with a code reader and see if it’s in spec or dropping out when under a load and it could be the root of all your problems

 

okay perfect I'll check and see what I can do thanks for the feedback! I'll keep you updated.