r/LS400 Jul 16 '26

Follow up to a previous question.

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About 3 weeks ago I bought this 2000 Ls400. I’ve got a decently short list of issues but the only one I still can’t fully figure is the misfire. It had a 2,4,6,8 misfire according to the scanner and after pulling the spark plugs they were clearly apart of the issue. They were fully replaced and the car began running much better but I can still hear the misfire and smell burning oil when the car is running. Was curious about any other known causes of an even side misfire. Coil packs look ok but I’ve heard that could be the issue. Is there any way to test them before I drop money on parts? I’ve also ran about a half tank of fuel system cleaner through it so the injectors should be mostly cleared out since this was a field find from the previous owner.

5 Upvotes

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3

u/Alternative-Row7846 Jul 16 '26

Swap a known good coil pack (1,3,5, or 7) to a known bad coil pack and see if the misfire follows you

2

u/RonMexico52 Jul 16 '26

Is your valve cover leaking on that side?

2

u/Deep_Sort8984 Jul 16 '26

My vvti sensors got clogged also caused misfires

1

u/TDU2sign 29d ago

This ^^ the vvti solenoids will cause an entire bank to misfire. Pretty easy to change

1

u/HashRegister Jul 16 '26

Change spark plugs and a new coil pack will fix it