[Solved] Golf V 1.9 TDI 105km Turbo Issues: P0299 Error, Pressure Controller, and Catalyst Inspection

Hello, I have golf 5 1.9 Tdi 105km. In golf, he cuts off my turbine. I led the car to a mechanic who immediately regenerated the turbo, but the problem did not stop. I went to connect the computer and the error P0299 jumped - the circuit of the turbocharger sensor A low pressure. I noticed that when I go at high speed (so to speak I give him) then I do not cut it off, and as soon as I put in the fifth gear and start driving calmly he cuts it off immediately. When I turn off and start the car, everything returns to normal, but for a moment. I checked the hoses and they seem to be ok. I bought a used pressure controller (because another mechanic recommended it) but the problem persists. Tomorrow the car returns to the mechanic because he wants to look into the catalyst. Anyone know what could be the reason? thank you in advance for your help.

Tightness of all tubing connections. I know you have already watched them. After all, see again. The catalyst would have to be blocked. The reason may be damage to the previous (before regeneration) turbine and oil that flew into the catalyst. However, the symptoms do not necessarily indicate this.

I noticed that the pipes going to the culer are wet with oil, but after pulling them the blow was normal, so there will be nothing blocked.

Added after 59 [minutes]:

I also noticed that when adding gas you can hear a distinct hissing and the pipe that goes to the EGR valve has a strange looseness.

I meant thin tubes. Of course, these thick ones do not hurt to check and seal. There may be a malfunction in the EGR valve or control.

Checking for flight tightness. Because there is a problem

case closed, air intake pipe cracked.