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Haven't physically looked for the ignition capacitor myself yet, but from the electrical schematic location description (mine is a NA XJ8 so I can't give you a direct comparison).......it likely has a mounting tab on it to secure it under a screw or bolt to the cylinder head or another larger bracket.
As for the separate earths mentioned in the above posts, both coil banks share the same common earth point an 12 volt supply point.
What is different is each bank's fuel injectors are serviced by two independent wiring harnesses that both plug into the engine bay harness via 6 way connectors at the rear of each cylinder head.
It is possible you have a tainted or corroded connection on pin 1 (12 volt supply) of the respective 6 way connector that is reducing the supply voltage to that bank of injectors.
The ECM may detect reduced current consumption of injector(s) but thre is no direct feedback within the injector itself back tothe ECM to report any operational performance issues.
have you checked the special bolt that doesn't interfere with the readings on the knock sensor is in the correct place at the top/back of the valve cover on the relevant side?
??????????? huh no never heard of that either. Just swapped upstream 02 and checked plugs on that side, reset ecm and same 2-4-6-8 came rt back
Haven't physically looked for the ignition capacitor myself yet, but from the electrical schematic location description (mine is a NA XJ8 so I can't give you a direct comparison).......it likely has a mounting tab on it to secure it under a screw or bolt to the cylinder head or another larger bracket.
As for the separate earths mentioned in the above posts, both coil banks share the same common earth point an 12 volt supply point.
What is different is each bank's fuel injectors are serviced by two independent wiring harnesses that both plug into the engine bay harness via 6 way connectors at the rear of each cylinder head.
It is possible you have a tainted or corroded connection on pin 1 (12 volt supply) of the respective 6 way connector that is reducing the supply voltage to that bank of injectors.
The ECM may detect reduced current consumption of injector(s) but thre is no direct feedback within the injector itself back tothe ECM to report any operational performance issues.
Never has this car seen water only when being washed. I havent touched anything near that connector ever. Car is always garaged it's whole life.
Swapped 02 sensors up stream, check plugs all looked good. Same codes came back after resetting the ecm. I can hear a rattling noise hard 1-2 shifts when the r's are coming up, then 2-3 high rpm BOOM restricted perf. Need to see live data
The rattling noise is NOT a ping at all it honestly sounds like cat material all broken up lol. I am straight piped and I never see any material flying out lol
Never has this car seen water only when being washed. I havent touched anything near that connector ever. Car is always garaged it's whole life.
Swapped 02 sensors up stream, check plugs all looked good. Same codes came back after resetting the ecm. I can hear a rattling noise hard 1-2 shifts when the r's are coming up, then 2-3 high rpm BOOM restricted perf. Need to see live data
This is all the 2 wire ones i can see rt behind the intercooler. BUT
why would it ONLY act up 2-3 high rpms?
Just AMAZING that this on a google search is fairly common on MANY cars and NO ONE NOT ONE LIVING CREATURE EVER POSTS THE CURE THAT FIXED IT!?!?!? WWHYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY ?????????????????????????????????????????????????? ?????????????????????!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!! LOL
Last edited by OnebadassXJR; May 30, 2025 at 09:23 PM.
Just AMAZING that this on a google search is fairly common on MANY cars and NO ONE NOT ONE LIVING CREATURE EVER POSTS THE CURE THAT FIXED IT!?!?!? WWHYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY ?????????????????????????????????????????????????? ?????????????????????!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!! LOL
cats fall apart on the 04-05s pretty often, dead giveaway is pinging and full bank miss. ebay ones and cheapo high flows are gonna melt quick fyi.
I have used the same co's cats MANY x and never had an issue, it is a "purists" thing where some one would rather spend 2k on oem cats vs $132 shipped just because it doesn't say Jaguar lol. I have 6k total into this car It is getting EBay cats Ill survive.
I'll be putting these in this Friday Night. Ill report back and HOPE this was the issue.
Did this guys cats on an SRT Jeep 2009 about 4 years ago still going strong. https://www.ebay.com/itm/166942047879
thanks man, what id really like is something like HPtuners for this generation of Jaguar. Something I can purchase a license then go in and delete the rear O2s and do some other things too. Then I’d just gut the cats and sleep like a baby at night.
Im emissions exempt BTW by title and population density if anyone has concerns.
HPtuners supports the next gen Jaguar, 10 and up, but not 04-09
Unreal the difference. These must have been clogged from day one and just got worse. The car is a different animal on all levels!! I have vids but it will not let me upload. BEST $132 shipped I ever spent!!
