Hello
I rarely post here unless it's something serious that I cannot figure out on my own, after making several attempts. I have a 2001 Lexus LS 430 with 133K miles. About six months ago, the engine started idling roughly. And also seemed to have a hiccup, of sorts. Every few hundred revolutions, the engine will skip.

Finally, a code appeared and check engine and VSC lights appeared. P0303, cylinder misfire 3.

Met with my mechanic. I had him install the plug and I installed the new coil.

A couple weeks later. Same problem. Hiccup misfiring again. So frustrating. Mechanic said wait for a code to appear and it finally did ... weeks later, two days ago. This time, it's P0308, cylinder 8 misfire. So, I swapped The new cylinder 3 coil on cylinder 8. Started it up. Still hiccuping.

Went and bought a new coil and spark plug from Lexus, all OEM parts and installed them asap.

Cleared the codes. Took it for a nice short drive with some easy roads and some speed as well. I get home. Put it in park. Listen to the idle and feel the steering wheel idle vibration. It misfires/hiccups again.
Intermittently.

I am at a loss on where to go next. I've also tried Chevron Techron fuel system detergents as well as Lucas before and during these part changes. No change.

Any advise you have to offer would be much appreciated.

Thanks,

bradicus

 

Does anybody have any advise to offer me? I would really appreciate it.

i installed the new coil pack and new plug. All genuine Toyota parts. Cleared the codes. And the engine is still misfiring. No codes. No CEL or VSC lights.

 

Did you ever solve this problem? I am having a similar issue with check engine blinking and vsc off light on.

 

Blinking check engine light (MIL) is a serious condition. It indicates catalyst overheating caused by severe misfiring (detected during any particular 200 revolutions of engine). You should refrain from driving your car until the problem is resolved.

 

Dumb question but are you 100% sure you're working on the correct cylinder?

This is the cylinder numbering of the 3UZ-FE...

 

Spray some Throttle Body Cleaner into the throttle body. This may improve your rough idle, and reduce stress on your car temporarily. Until you can stop it completely.