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I have a 2012 optima SX. Other than having to have the engine replaced I've loved my car. One thing does bug me. I have notice that the lag time between pressing the gas petal to when the power comes on. Some times it comes on quick. Like from a stop. However if moving at speed 30 mph and up it feal like there a delay. I assume the engineers programed in some kind of response curve related to speed, gear, boost or possible even steering angle (just a guess). I would like it to have a direct liner response from petal to throttle body.

I'm wondering if this can be addressed by some kind of tune, throttle body upgrade or other aftermarket part.
 

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OP, do you use eco mode? I hope not, lol
Any check engine lights? The waste gate actuator voltage could be off.
I have never cleaned my intake, not sure what that entails. Maybe bigbx can enlighten us...
 

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Well the turbo always has some sort of lag, are we talking several seconds or just longer than you'd like? The intake cleaning helps especially with idling yet can affect the overall performance. Since these are GDI engines with no pre-intake injector, an intake cleaning helps about every 60K or it will simply cake up to the point the engine just about chokes for air, you've seen the pics of carbon encrusted intakes.

But yes could also be misadjustment of wastegate voltage, so check that too.
 

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2014 Kia Optima
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Well the turbo always has some sort of lag
This was my first thought as well. It's called turbo lag. When you're already cruising at speed, and then step on the pedal, there's a bit of a delay between when you press the pedal and when the car starts to accelerate at a rate that matches the throttle input. It's normal and is exactly how a turbo works. It takes the engine's exhaust and uses that to spin a turbine that compresses the engine's intake air, giving it more power to spin the wheels. It's this returning of "power" to the intake that causes the turbo delay (aka lag).
 

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I take it back, I think I did an intake cleaning once with a known product. Made no difference except it took a while to get it thru the system and back to normal...
 

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I have notice that the lag time between pressing the gas petal to when the power comes on. Some times it comes on quick. Like from a stop. However if moving at speed 30 mph and up it feal like there a delay.
It sounds to me like maybe your transmission is slow to downshift. If you are cruising at 30 and then stomp on the gas, do you feel the engine bog down as if it's trying to accelerate? And when it finally does accelerate, is there a hard downshift? I will echo a previous response and say you should verify you have eco mode turned off.
 

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2014 Optima SX 2.4 GDI (no turbo)
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I have a 2012 optima SX. Other than having to have the engine replaced I've loved my car. One thing does bug me. I have notice that the lag time between pressing the gas petal to when the power comes on. Some times it comes on quick. Like from a stop. However if moving at speed 30 mph and up it feal like there a delay. I assume the engineers programed in some kind of response curve related to speed, gear, boost or possible even steering angle (just a guess). I would like it to have a direct liner response from petal to throttle body.

I'm wondering if this can be addressed by some kind of tune, throttle body upgrade or other aftermarket part.
I have a 2014 SX, no turbo. I've driven many a car in my day and this is the only car I've ever driven that has such a significant delay in throttle response after I push the pedal. It's one of the only things I don't like about my car. I asked my local Kia dealer about it after I first bought it and the local service manager said these just tend to be like that right from the factory. And offered no fix (I've always done all recommended maintenance, throttle body cleaning, etc). Fast forward a few years and my regular local mechanic who I go to for tires and brakes, etc, (not the dealer) heard me complaining about this too, and he told me he also has the same issue (he happened to have the same car, except his is turbo...so yes, it affects turbo Optimas also). The solution he suggested to me is an aftermarket "throttle controller" that he had purchased, and he recommended specifically the X9 model from this company which he said works to fix the issue:


I didn't like the white face on the X9 and bought the more expensive XS model but the connector it did not fit my car even though their online selector tool said it would. Should've listened to my mechanic (he also went through this not fitting issue apparently). Swapped it for the cheaper X9 which took some time with shipping back and forth, and finally, the X9 does fit (they credited me the difference in price), and boy did it solve the sluggish throttle response (which is totally different from turbo lag). Although they don't show it in the picture, the X9 model comes with a black face you can stick over the top of the white one if you prefer black (matches my black leather interior better). Now this unit in the "Racing Mode" is entirely too sensitive for my taste and may even be downright dangerous in certain situations (best to turn it off when backing up in a busy parking lot for example). The beast will jump if you barely touch it in this setting. I prefer "Sport" mode which is slightly less aggressive but more than solves the problem. There is also Cruise Mode, Economy Mode, Automatic mode (tries to compensate for all conditions), and OFF (you can disable it so it acts like stock again). This thing is ridiculously simple to install. Just unplug the electronic throttle connector from the top of your gas pedal, put a small box in between (snaps in both ends from what you removed), then connect the interface box (what is pictured) which plugs into the other little box you added above your pedal, position it on your dash, and you're ready to roll... and finally I can pass quick, start fast from pulling out turning from one roadway to another, all without having to keep the pedal mashed to the floor... A responsive car with a competent and even moderately aggressive (but still defensive driver who yields to idiots) is way safer, IMO. But the car has to GO when you want it to GO. Hope this helps you and perhaps others who read this and are bothered by the throttle lag in these Optimas. HikeIT should pay me a commission for referrals, ha ha.
 

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I have a 2012 optima SX. Other than having to have the engine replaced I've loved my car. One thing does bug me. I have notice that the lag time between pressing the gas petal to when the power comes on. Some times it comes on quick. Like from a stop. However if moving at speed 30 mph and up it feal like there a delay. I assume the engineers programed in some kind of response curve related to speed, gear, boost or possible even steering angle (just a guess). I would like it to have a direct liner response from petal to throttle body.

I'm wondering if this can be addressed by some kind of tune, throttle body upgrade or other aftermarket part.
I have a 2012 Optima EX.and it has that same lag at that speed. But from a stop, it will burn rubber. 145,000 miles got 6 months ago. I think this is normal and just the design built into the car but I may have carbon built up. but I don't know. I only use Costco gas because it has really good cleaner in it, I heard. What's a good additive for carbon build-up?
 

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I have a 2012 optima SX. Other than having to have the engine replaced I've loved my car. One thing does bug me. I have notice that the lag time between pressing the gas petal to when the power comes on. Some times it comes on quick. Like from a stop. However if moving at speed 30 mph and up it feal like there a delay. I assume the engineers programed in some kind of response curve related to speed, gear, boost or possible even steering angle (just a guess). I would like it to have a direct liner response from petal to throttle body.

I'm wondering if this can be addressed by some kind of tune, throttle body upgrade or other aftermarket part.
I had a 2013 Optima Hybrid EX and the acceleration delay almost got me in a couple of wrecks. Nothing like seeing a clear spot to pull out into traffic and by the time you push it to the floor, the car didn't move for a second or two. You have to adjust you driving to count for the delay. It felt very dangerous!
 

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2014 Optima SX 2.4 GDI (no turbo)
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I had a 2013 Optima Hybrid EX and the acceleration delay almost got me in a couple of wrecks. Nothing like seeing a clear spot to pull out into traffic and by the time you push it to the floor, the car didn't move for a second or two. You have to adjust you driving to count for the delay. It felt very dangerous!
Amen brother.
 

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Start simple. A can of Techron concentrated injector cleaner or Seafoam injector cleaner gets added to my gas tank whenever my 2.4 Optima 2012 starts to hesitate when shifting gears. Problem then disappears for a couple thousand miles. Without this additive my Optima would totally annoy me.
 

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2020 Kia Soul X-Line 2.0 MPI
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Start simple. A can of Techron concentrated injector cleaner or Seafoam injector cleaner gets added to my gas tank whenever my 2.4 Optima 2012 starts to hesitate when shifting gears. Problem then disappears for a couple thousand miles. Without this additive my Optima would totally annoy me.
^^^^^^^^^^^^^THIS^^^^^^^^^^^^^^
Both Techron Concentrate for the gas tank and CRC GDI Intake Cleaner for INSIDE the throttle body.
 

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I have a 2014 EX with about 65k miles, and I don't experience any hesitation at any speed or in any gear unless I have the Eco setting turned on. So maybe it is an issue with higher miles.
 

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Well given that the OP has not been back, maybe he was using eco without knowing it...
 
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