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Discussion Starter #1
Hi,

I have a 2014 Mazda 3 BM 2.0 A/T 120 PS. The car was unlocked / tuned to 170 PS and 220 Nm. After almost two years after unlocking I found out that the car lost its power.

The top speed after chiptuning was 215kmh (133mph). Now the car cannot go over 185kmh (115mph).

I did a DYNO test and not it has only 159PS and 199Nm (see attached dyno chart - the bolded lines are now, the other just after chiptuning).

There is a huge drop around 2k RPM .

Any guesses? I thought about exhaust leak but did not see any.

 

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Who did the tune? There is no such thing as a chip tune for the Mazda 3 SkyActiv cars. Its possible that whatever was done to the car was outside of safe parameters and did some damage over time.
Other than that, have you done any checking under the hood at all? Plugs, coils, any basic diagnostics?
 

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Hi, I have a 2014 Mazda 3 BM 2.0 A/T 120 PS. The car was unlocked / tuned to 170 PS and 220 Nm. After almost two years after unlocking I found out that the car lost its power. The top speed after chiptuning was 215kmh (133mph). Now the car cannot go over 185kmh (115mph). I did a DYNO test and not it has only 159PS and 199Nm (see attached dyno chart - the bolded lines are now, the other just after chiptuning). There is a huge drop around 2k RPM . Any guesses? I thought about exhaust leak but did not see any.
I'd be willing to bet, you need to change your coolant, spark plugs and air filter Hopefully you've also been changing your synthetic oil every 5-7k too. That kind of power per liter output has a tendency to cut the maintenance cycles in half in order to keep the power up. So if the factory plug replacement cycle is 60k, it's now 30-40k to keep the power output up. The higher the horsepower per liter output typically shorter maintenance cycles are required. Also the 2k power drop off really points to your spark plugs and coolant as likely cultprits.
 

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It would also be helpful to know how many miles are on the vehicle now. All cars lose power over time and wear.
 

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Discussion Starter #5
car has 65k miles.

spark plugs are new. air filter also

I have never changed the coolant yet so I will probably do that and check.

the car did 120HP on stock and around 165HP-170HP after tune which is normal (some cars show even 180hp). The power drop is easy too see while driving top speed which dropped a lot.

also this torque drop around 2k RPM is strange
 

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I'm more interested in in the chip tuning you mentioned instead of coolant. For diagnosing s power loss, changing coolant isn't going to do much if it's keeping the engine cool. It would have to be pretty sludged up or there be a blockage forming to make any noticeable difference to power output. Still, I can't argue with regular maintenance so yes change it. I just wouldn't hold my breath about it fixing anything.

This chip tuning ... usually when you hear this it involves a resistor in line with the MAF singal, coolant temp signal, etc. To modify those values received by the ECU. Problem is they rarely work right.

So the question needs to be asked again since it was never answered: who did this chip tuning? What exactly was done?

It's entirely possible that the tune is causing the power loss or has caused some damage that has caused drop in power. We need to eliminate this as a variable before we can continue troubleshooting.

And finally....has a code scanner been used?

You can always try pulling the battery cable to reset the ECU....
 

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Sounds to me like something has happened as a result of this tune. More information on what was done and how is needed.
If you have a 2.0L SA-G motor, its normal output is 155-165 hp. For some markets it is detuned as is yours. Tuning will remove the limitations and the engine will respond as a normal 2.0L SA-G would, ie you move into the 170 - 180 hp range depending on the octane requirements you selected. That small increase in power should have no effect on engine durability or change the maintenance schedule in any way. If the tune was done wrong, you might have damaged the engine or the catalytic converter. You would need to do some diagnostic work to see whats going on.
 

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Discussion Starter #8
That's exactly what was done. Car was detuned from factory and therefore it was "unlocked" to have as much power as it should from stock.

After this "chip tuning" everything was okay. Dont know what could have happened during one year after it, while the car did only around 7k miles during this period of time, 90% of which was on local routes with speeds less that 30mph

I will check the car with forscan today but i don't think any DTCs are there.
 

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We still don't know what exactly was done to 'unlock' it. Diagnostics is more of a process of elimination than anything. Without ruling the tuning out, we can't do much.
 

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Just spitballing here but did you ever notice a gas smell from your exhaust any time after the tune? I'm wondering if your engine was running too rich, rich enough to eventually melt/clog the cat.
 

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That's exactly what was done. Car was detuned from factory and therefore it was "unlocked" to have as much power as it should from stock.

After this "chip tuning" everything was okay. Dont know what could have happened during one year after it, while the car did only around 7k miles during this period of time, 90% of which was on local routes with speeds less that 30mph

I will check the car with forscan today but i don't think any DTCs are there.
Who did this tuning? There is no such thing as a chip tune for any new Mazda. What exactly was involved in doing this? Have any data logs been recorded, or just the dyno results?
 

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Hi,

I have a 2014 Mazda 3 BM 2.0 A/T 120 PS. The car was unlocked / tuned to 170 PS and 220 Nm. After almost two years after unlocking I found out that the car lost its power.

The top speed after chiptuning was 215kmh (133mph). Now the car cannot go over 185kmh (115mph).

I did a DYNO test and not it has only 159PS and 199Nm (see attached dyno chart - the bolded lines are now, the other just after chiptuning).

There is a huge drop around 2k RPM .

Any guesses? I thought about exhaust leak but did not see any.

You crack me up. Why would you take such a risk as to modify a superbly engineered engine so you could gain what, a little more speed? You gotta be kidding. Unlocking/chip tuned? It's not a cell phone. Now what? Are you gonna f*ck it up even more till you totally ruin your once fine car? Maybe you learned a lesson but I wonder. Why didn't you just buy a different car with more power if that's what you wanted? These cars are computerized complicated machines. Mazda spent millions of R&D developing these engines and when you go dickin' around with no idea what the hell you're doing, what do you expect? I can hardly wait for the update to this story and how you wound up totally destroying a perfectly good car. And then are you going to say Mazda's suck! Don't buy one. They don't last 60k miles. Amateur hour. I hope others reading this with similar aspirations learn from this. Leave your car alone. Why not write to Mazda and tell them what you did and how to fix it. I'm sure they'll have more of a laugh than I am. One final thought. You say you drive it slow all the time. Why did you even do it if you're not going to drive over 30 mph?? Direct injection engines are prone to carbon buildup. Have you used a boroscope to check the valves for carbon buildup?
 

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You crack me up. Why would you take such a risk as to modify a superbly engineered engine so you could gain what, a little more speed? You gotta be kidding. Unlocking/chip tuned? It's not a cell phone. Now what? Are you gonna f*ck it up even more till you totally ruin your once fine car? Maybe you learned a lesson but I wonder. Why didn't you just buy a different car with more power if that's what you wanted? These cars are computerized complicated machines. Mazda spent millions of R&D developing these engines and when you go dickin' around with no idea what the hell you're doing, what do you expect? I can hardly wait for the update to this story and how you wound up totally destroying a perfectly good car. And then are you going to say Mazda's suck! Don't buy one. They don't last 60k miles. Amateur hour. I hope others reading this with similar aspirations learn from this. Leave your car alone. Why not write to Mazda and tell them what you did and how to fix it. I'm sure they'll have more of a laugh than I am. One final thought. You say you drive it slow all the time. Why did you even do it if you're not going to drive over 30 mph?? Direct injection engines are prone to carbon buildup. Have you used a boroscope to check the valves for carbon buildup?
You need to do a little research before you post......tuning the SA-G is done all the time with excellent results. Detuned Euro market 2.0L engines being retuned back to the original Mazda specs is fairly common. You obviously know nothing about SA-G motors and how they work...
 

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Discussion Starter #14
yuup that is true. european cars with A/T have 120hp while US spec 150. Same cars with M/T give 170hp.

Taking into account the fact that mazda 3 2.0 transmission is the same as in 2.5 192hp you can unlock your EU SPEC 2.0 A/T from 120 to 170hp

and yes i could smell gasoline from exhaust
 
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