It's possible. Your alternator could cause the system to lag due to a charging issue, or it could be giving the ECU a hard time making a fuel distribution delay. EFI cars are very sensitive in this sense. You may want to check your alternator, the alternator belt, and the wiring.
I know when I'm going about 40 or so and I floor it the car takes a second or two to kick in. The rpm's jump and then the car starts to accelerate. That's just something all the auto mustangs do...but usually most tunes will fix this, since the shitty factory settings are replaced. The pressure points and firmness in shifts are greatly improved with a custom tune that's tailored to this.