Performance issues

[Xitro]

Hi guys,

I've been haunted by performance issues quite some years now. After my chiptune to 210 hp it ran great. Until it someday just didn't want to pull as much as it did before.
I've tested my car on a bench again and it only gave 155 hp. Went back to my original tuner, where it gave 210 hp on a bench again. It's an on/off issue, sometimes it pulls great, but mostly not.
My garage/tuner don't know or don't see the issue. So I hope you guys can help me out.

Mods on my car before the tune/problems:

• Forge SPLT-R
• K&N drop-in filter

Mods that I did after the problem occured (to try to solve it):

• CAI with Injen filter
• FMIC (CXRacing)

Symptoms:

• Since the issue I hear a lot of sucking or blowing of air noise.
• Shortly I start hearing a ticking/rattle from the intake manifold under full load.
• Sometimes it pulls great, but mostly when I try to pull it takes forever to get to 60mph.
• Since the problem it feels that I only have good acceleration after 3,5K RPM.
• According to my tuner I have boost at 3K RPM which is quite late according to them.

Errors in VCDS (have reset them every time/keep coming back):
27-08-2015:

• 16683 - Boost Pressure Regulation - P0299 - 002 - Control Range Not Reached

23-10-2015:

• 17535 - Fuel Trim: Bank 1 (Mult) - P1127 - 002 - System too Rich - Intermittent
• 16825 - EVAP Emission Control Sys - P0441 - 002 - Incorrect Flow - Intermittent

29-04-2016:

• 17535 - Fuel Trim: Bank 1 (Mult) - P1127 - 002 - System too Rich - Intermittent
• 16683 - Boost Pressure Regulation - P0299 - 002 - Control Range Not Reached
• 17700 - Map Controlled Engine Cooling Thermostat (F265) - P1292 - 004 - Open Circuit - Intermittent

08-11-2016:

• 16683 - Boost Pressure Regulation - P0299 - 002 - Control Range Not Reached
• 16825 - EVAP Emission Control Sys - P0441 - 002 - Incorrect Flow - Intermittent
• 17700 - Map Controlled Engine Cooling Thermostat (F265) - P1292 - 004 - Open Circuit - Intermittent

I have a couple of logs available as well if you would like to check it out.
Hope you guys can help me out, thanks in advanced!