Hello all, I have a 2017 wrx which is stock except for a flex fuel kit and custom professional e-tune. Kit and tune were installed approximately 1 year ago. I've been commuting a lot more recently and have noticed that the car is a bit unpleasant to drive. When accelerating 25-40% and then lifting off (i.e. stop and go traffic), the car bucks a decent bit. Almost like excessive engine braking. I notice it more in gears 2-4. I don't always remember the car behaving like this but I also may just be hypersensitive to it since I'm driving a lot more now post-pandemic.
Either way I want to try and diagnose whether the stock map also behaved like this or is it because of the e-tune. Can I flash to the stock (stage 0) map and drive the car while the FF kit is installed or will it throw a CEL? I'd obviously be running 100% 93-octane pump gas while doing this. I'd rather not have to remove the FF kit to perform this little test but if I have to then it is what it is.
Thank you kindly in advance.