Hey guys - I actually scheduled some dyno time for today and reflashed the car back to the stock 400 tune yesterday in anticipation of doing back-to-back runs. I drove it around for 30 minutes today before going to the dyno, did a pull (362whp in 4th, then later on 373whp in 3rd), then tried to switch over to the 435 tune and no matter what I tried, I was getting "unable to start communication with ECU" error. Removed then reloaded the K-T software onto my laptop, turned car off and on multiple times, etc, tried it every which way and nothing changed. Came home, hooked it up to my battery tender (every time I have changed the flash, it has been hooked up) and even tried a new OBD cable, but that didn't do the trick, either. I sent an email to K-T just now with copies of the screen shots.
For what it's worth, looking at other stock car dyno graphs at their shop it seems like the 400 is underrated. A stock 2008 BMW M3 put down 338whp and a 2017 GT350 put down 455whp.
One other issue that may or may not be related is that my airbag light comes on sometimes since I first did the 435 flash and even with the OE 400 flash today. It comes and goes but mainly stays on. Lord knows what's causing it.
UPDATE: after letting the car sit for an hour, I gave it one more try and voila it worked! I was able to download the 435 flash no problem. I've emailed the dyno guy to see when I can try again.
Last edited by Champale; 05-27-2019 at 09:01 AM.