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broken IMRC shaft causing P030X codes

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I've had the P0308 and P0300 (#8 misfire and multiple random misfires) for about a year now on my 2015 GT with about 48,000 miles. I pulled my intake off and found the driver's side IMRC shaft was broken (5,6,7,8 cylinders). My mustang isn't a daily driver, and the codes were clearing up on their own until last week. The idle was rougher, and the highway fuel economy was down from 26 to about 22 mpg. A new intake is on order. I ordered online from a Ford dealer for around $320. I hear you can get it cheaper if you know the right people on forums.

I first thought I might have the crank position sensor issue, because the car didn't seem to be driving poorly. After the codes stayed on last week I decided to search the forums again, and went ahead and removed the intake.

Video showing the broken driver's side IMRC shaft (it's metal and not plastic as I say in the video):

Picture of the broken shaft:
20190705_broken_imrc_shaft.jpg
 
To the best of my knowledge a new intake comes with the gaskets, vacuum mechanisms, sensors, etc. That's what the parts guys on the phone said. I tried pulling the broken rod out of the butterflies on the stock intake. It appears to be sealed in on the front end by a plastic welded cap. I could probably drill through it, extract the rod, replace and reassemble.
 
1,246
1,243
In the V6L
Was there a reason you didn't just get Ford to fix this under the 5-year power train warranty? Was it a super early production unit made before July 2014?
 
I've had bad luck with local dealerships service departments causing more problems, and many of the broken IMRC misfire warranty fix stories on the forums involve multiple trips until someone can be convinced that the shaft is the problem. I'll do it faster and correctly at home.

I didn't want to do an 18 intake, because I don't want to tune the car at all. It's stock other than the resonator being cut off by the previous owner. I don't know how much longer I'm going to keep it once it's fixed (sync keeps kicking my phone off media player and the backup camera is dying). I have had really bad luck with ford electronics, clutches, PTO boxes, and service centers trying to deny warranties. My 2010 F150 has been great, but the 2012 focus, 2013 explorer, and now the 2015 GT have all had multiple electronic and drivetrain issues. It's why my wife is now driving a highlander, and I'm looking at STIs for a daily driver.
 

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