TDi Tuning: Is It Possible?

Hello again,

As previously explained in a different context, it appears that it is not possible to achieve a performance increase with a chip tuning solution for my 1Z engine.

Now the question: Besides the turbocharger and the mass airflow sensor, which components could cause a vehicle, equipped with a chip that supposedly regulates both boost pressure and fuel injection differently and delivers 118 horsepower, to perform with the same power output as a 90 horsepower car?

What should one search for?

Hello,

What should you be looking for? Ideally, you should look for a decent tuner.

Why don't you just try the 10ct tuning? (Of course, test it out on private roads.)

Okay, I mean, the easiest solution is to just change the tuner and say that it doesn't know what it's doing.
But why would he bother soldering in a chip that he claims to have sold multiple times before, and that has always worked perfectly, if it's going to achieve nothing and I'm then going to demand my money back from him?

He said that if the chip wasn't soldered correctly, the car wouldn't even start. He also showed me the original data and the modified data on the chip on the computer. What else could another tuner do besides installing a chip themselves and hoping for a reaction from the car?

You won't get anywhere with guesswork. Or do you want to simply replace the turbo, ESP (Electronic Stability Program), mass airflow sensor, fuel injectors, catalytic converter, etc., until you find the problem?

Get a diagnostic adapter and start searching!

So, in terms of diagnosis, I mean that the error memory doesn't show any codes, and the mass airflow sensor and turbocharger were tested during a test drive (and the data is within normal limits) at VW.
What else could one possibly "diagnose"?

I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.
Okay, I'm ready. Please provide the German text you want me to translate.