[copeterra]

Thanks @General_Tarfun. Get this, the issue is back. I don't know how it was ok for a week and it start misfiring again and throwing a blinking CEL when I accelerate hard. Misses quite a bit around 2000 rpms at around 45mph. ......sigh

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[General_Tarfun]

Thanks @General_Tarfun. Get this, the issue is back. I don't know how it was ok for a week and it start misfiring again and throwing a blinking CEL when I accelerate hard. Misses quite a bit around 2000 rpms at around 45mph. ......sigh

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Any codes showing up yet? If it can pick a cylinder with a problem I'd swap that coil pack with another cylinder and see if the misfire follows the pack. Be careful with the misfiring you don't want to blow the cats out, if possible take it easy and try to avoid any more of them than absolutely necessary. Were your spark plugs tubes clear of oil back when you replaced them?

 

[copeterra]

No codes yet. Does miss a little while idling now. The plugs didn't have any oil on them. Manifold had a good but of blowback oil in it if that matters. Just strange the issue vanished and came back. Would doing the long "relearn" process do anything?

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[General_Tarfun]

No codes yet. Does miss a little while idling now. The plugs didn't have any oil on them. Manifold had a good but of blowback oil in it if that matters. Just strange the issue vanished and came back. Would doing the long "relearn" process do anything?

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The manifold oil shouldn't cause a misfire that bad, maybe a rough idle at most although I have heard of intake manifold leaks causing problems like that before, did you have a chance to replace that bolt yet? I know you had that leak on the passenger side before, the crankshaft position sensor is on that side below that connection, I wonder if any of the coolant was getting onto it?

I'm looking through the FSM for more info, here's what it list to check out for misfiring:

 

[Brunnie]

Wild suggestion here....

Any vacuum leaks?

 

[copeterra]

The manifold oil shouldn't cause a misfire that bad, maybe a rough idle at most although I have heard of intake manifold leaks causing problems like that before, did you have a chance to replace that bolt yet? I know you had that leak on the passenger side before, the crankshaft position sensor is on that side below that connection, I wonder if any of the coolant was getting onto it?

I'm looking through the FSM for more info, here's what it list to check out for misfiring:

Thank you again for your help. It's SO appreciated @General_Tarfun. I cleaned everything I could get to on the intake manifold. I have not repaired the broken manifold bolt yet. I wonder if it's taking in air. It is the first bolt near the radiator.

It seems this all started when I did have that coolant leak dripping down. It did cover that 02 sensor for about 3 weeks. I believe that to be the 02 oxygen sensor. I did get a few codes for rich and roo rich but they went away when I fixed the leak. Shoddy plastic heater hose inlet.

I guess my next step is 02 sensor, coils, compression check, and maybe checking the cats. IIRC, ever once in a while a do smell a faint rotten egg smell.

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[copeterra]

Wild suggestion here....



Any vacuum leaks?

I did spray some mass air cleaner over most of the engine while it was on and didn't get any rpm fluctuations.

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