Your ECU had pulled a bit of timing to prevent detonation at that rpm range. The reset cleared that timing correcton. The next time you cause detonation in that rpm range the hesitation will come back.

You might have gotten some bad gas, or done something else that pushed the car over the edge just a bit.

Larry

 

It's normal for the ECU to taper boost down at high rpms with a stock turbo. Your engine doesn't make as much power on high end as it does in mid range, that's why it feels slower up there.

 

Yes it's protecting the engine. Your most prone to detonation at rpm's near the engines torque peak because that is where you have your highest cylinder pressures.

It means your running a bit too much boost, you have a small air leak on your intake, or dirty fuel filter or low fuel pressure making you to run a bit lean, your fuel is a bit low on octane, perhaps you need to run a one step colder plug, or you had very high engine load for some reason, like you had a car full of people and decided to flog it a bit on a hill.

Look around at different brands of fuel. For a turbocharged car there is a difference between fuel brands. Stay away from the el-cheapo outlets. Some folks have reported they have had problems with Shell premium. In other locations it might be a different brand that is a bit off the mark.

Gas stations and fuel delivery drivers do occasionally make mistakes and put fuel deliveries in the wrong tank. Some cheap outlets intentionally miss blend fuel.

On some cars, they have problems with winter blend gas and run fine on summer blend. In other areas cars like the winter blend but don't like the summer blend.

I've had good luck with Conoco and Phillips 66 fuel here in Colorado. Each fuel outlet blends its own fuel so a fuel that is good in one part of the country may not be as good in another because EPA regulations force different parts of the country to use different gasoline blends. That is one of the reasons we have local gasoline shortages, becasue they cannot legally move fuel to different distribution areas when a local shortage develops.

Larry

 

is that normal(boost dropping)...i ve had boost drop like that when i step on the gas and shift through my gears.