Tuning a stock bike
 

Will there be any benefit to adding a FP3 tuner and a stage 1 air cleaner to a stock 17 FLHTK? Will it make it run cooler, a little richer? I already did the bypass on the AC to a catch can.

i wish that I knew the answer to your question. When I had my 103, I was told that a tuner wasn’t necessary with either exhaust, or air cleaner; but was necessary when both were used. I have read that some, believe the same info about twin cooled. I don’t know, but like you, I’ll be watching for answers from those “know” from experience.

well if you believe the manufacturer a retune (ECM recalibration) is required when adding a high performance air cleaner "You must recalibrate the ECM when installing this kit. Failure to properly recalibrate the ECM can result in severe engine damage"..... so let your conscience be your guide whether to trust opinions here or the folks who designed, developed, produced and provide warranty....as far as FP3 and cooler or richer I have no idea...can't imagine being significant retaining OEM headpipes

No, its not required, but wont hurt, the stock Air Cleaner is pretty free flowing, so if one changes air cleaner, its more aesthetic than any different 'performance' of said air cleaner. Also, depending on warranty and how you feel, using the non Harley SE tuner may void the warranty. The ECM can and does handle the muffler and air cleaner change that is often referred as stage 1. When a cam swap is done or anything like that then you will need to retune the bike as the stock config of the ECM isn't set for that and that's really all your doing, basically advising the ECM of what the config is and it does it thing.

I say go for it. I removed my stock exhaust, full Cobra. Headpipe and Neighbor Haters...did a tune with the SE tuner and its more responsive on the throttle. I also run the SE ventilator air cleaner. I did gain a few MPG's...but no bump in power thats remarkable if at all.

I bought my bike used, it is a 2017, no warranty

Stock 17 you say? Well most would recommend that you change the oil pump to the newest design from HD as soon as you can. While doing that you may as well upgrade the air/cam/pushrods/lifters/tune into a stage II as the job to change out the oil pump involves handling most of these parts. You’ve got no warranty so aftermarket will give you the most options.
What I did…2018 Ultra LTD Anniversary Stage II
Street Cannons, HD 8 Lobe, K&N,
Fuelmoto Cam kit WM8-22X, S&S Cuffs,
PV Tune.

There is no benefit to adding Stage 1 and tune to an M8. The biggest bang for the Buck is do a stage 2.

simply an untrue statement..there is not huge benefit for sure..but overall driveability along with some performance increase that can be felt and appreciated is possible, even with the SEPST..I know this from experience..yes a proper Stage 2 is going to provide the seat of the pants performance increase a Stage 1 can't

The benefit of sound and aesthetics, weight savings when going to a shorter pipe, higher efficiency through better airflow. The “benefits” start stacking up and I can tell you, you feel it on this motor.

While waiting for my exhaust on back order, I got the improved stock tune from Fuel Moto and loaded it with the power vision. HUGE improvement.