CELs and Reduce Power - 2015 FR-S JRSC

[Escher]

Happy almost-Thanksgiving everyone! This year for Christmas, I just want my peace of mind and brake horsepower back!

For reference, this is in regards to a 2015 FR-S w/ ~85K miles on it, a JRSC w/ Delicious EcuTek E-Tune (14 months), and a simple muffler delete (6 months). Engine oil, tranny oil, sparkplugs, coolant, etc. all maintained in the last year.

Over this past summer, I encountered the first CEL I've gotten in 4+ years of owning this vehicle: WOT on an on-ramp, sudden drop in power, flashing CEL. This was after a couple weeks of a noticeable "hiccup" in power in several gears. It was diagnosed as a misbehaving ignition coil, and upon replacement, all bad behavior disappeared... for ~ 1.5 months.

Once again, I started getting the power hiccup, and based on:

1. Supercharger w/ no oil cooler
2. Midwest heat ~117 every day
3. Spirited driving

I assumed it was simply another failed coil, backed up by some forum suggestions. Replacing them again *seemed* to do the trick, however in the back of my mind I *felt* like something was off.

Fast forward to about a month ago, and suddenly power is starting to be noticeably reduced, random CELs (including our favorite flashers) with the ABS light also coming on and then off seemingly randomly.

Then, while idle waiting for a turn, she cuts off completely. This seems to go hand-in-hand with the fact that the CELs will pop up most frequently while idling.

In addition to this behavior, I started noticing a distinct smell of unburnt fuel in the exhaust.

As a final piece of information: w/ the EcuTek app open, monitoring misfires, the only cylinder I have been able to catch doing so is #3. That, combined with the fact that it is on Bank #1, which is the only bank I've ever seen called out in the CEL, is giving me a raging clue.

Here are the net collection of CELs that I have seen:

Engine CELs:


ABS CEL:


Additionally, I have taken the following EcuTek logs in 3 different scenarios:

• Startup to Idle
• 0-50 MPH non-WOT
• Warm Idle

I normally would not dump all of this onto a forum in desperation, but as much as I love troubleshooting and working on the vehicle, I am well aware that this these kinds of tricky engine issues can result in throwing expensive parts at the wrong problem.

I greatly appreciate whatever insight anyone can give into this, and a bottle of bourbon to the first person to help nail it down.

[tomm.brz]

you need to upload to datazap if yoy want us to take a look

[Escher]

Thanks - updated the OP:

• Startup to Idle
• 0-50 MPH non-WOT
• Warm Idle

[Escher]

Additional data points:

I just cleaned the MAF, cleaned the engine air intake, and even took off the throttle body to get at the solenoid EVAP lines to clamp them for peace of mind.

Immediately upon starting the car, intermittent flashing CEL persists.

I have the Ecutek logger up and it's reading ZERO misfire or even knocking, and no CELs at all.