Hi, I've been having irritating issues for the past 3 weeks that I haven't been able to solve.

Specs: 1.8T AYP K03s, Forge DV Yellow spring, N75F, High flow tip, KN Cone intake, Stage 1

I've been fixing issues since 3 weeks and still the low boost issues and low power persists. Changed N75 to F version and Map sensor (this made the car actually boost but it was still cutting. Changed fuel pump, fixed a boost cut problem. Fixed a cut boost hose, no better results. Now noticed a exhaust leak at manifold changed to a perfect used manifold and tested turbo. Wastegate cracks at 0.5bar. Boost leak test is ok.

The problem persists. Just did some logs today. Basically the car doesn't boost even past 0.5bar on 1st and 2nd gears. After 3rd gear it somewhat boosts to 0.8bar. This is with N75 ON and the n75 readings fluctuate around 70% WGDC and max out at 80.4% to redline on every gear. I took off the hose that goes from WG to N75. Car now boosts fine and follows requested! But the power is lower...

I basically did a better 0-402m time with 0.6bar and n75 connected, than with 1bar constantly and wastegate hose off.

Logs basically show WGDC from 65% to 80.4% maxed out. Timing retard is 0. Narrowband voltages are weird. 0.84v idle, 0.78 from 3-4k rpm then in random points it goes down to 0.4v and even lower. MAF is 159g/s at 6k rpm. Those readings are not bad. But the car isn't making power, I can feel it.

What in the world is happening? Bad n75, I've been changing two? Should I change to a 1mb wideband ecu, because the only thing that left here is the management system in this 512KB ECU. I should get an AEM AFR gauge and make sure I have fuel, then move on with solving the boost issue, even if it takes switching to a wideband ecu.

Forgot laptop at work. Will post tomorrow. Currently just trying to understand what could be causing this. There is no leaks in the system been tested couple times... just can't understand how its not boosting at all, or the solenoid wgdc is wrong and its not working. I actually got lower than wg pressure boost when I tested it on 1st and 2nd gears with n75 connected. Top hose off and it hits 1.1bars max.

Will update tomorrow.

dont waste your time. others have told him this as well and he refuses to believe, however obvious it may be.

I am sure because I've literally sent the turbo for testing flow tested and they adjusted wastegate and it cracks at 7psi like stock. They told me install the turbo its not a turbo issue. Installed new manifold new gaskets everything is tight no leaks. Boost tested AGAIN today it holds the pressure well.

I am suspecting throttle being closed due to fuel issue, maybe the fuel pump I changed was also bad.

Current narrowband voltages on a full throttle go from 0.8v to 0.7v then at random points it hits closed-loop and goes down to 0.5v and back up to 0.78v. Do I have a fuel issue? Because its supposed to be 0.9v to be rich. Getting an aem wideband soon.

Goes lean, or goes closed loop? These are two different things. I think it would be the other way round - throttle cuts in because of boost problems, kills load, ECU goes closed loop and drops the fuel to 1.0 lambda.

Anyhow, this is pointless academic discussion without proper logs.

Have you logged at all?  If that throttle is not closing and it's not making more than a bar with no WG line, you have a hardware issue.  Absolutely no doubt about it.

Here are the logs. Throttle body pos. sensor is at 87% and pedal sensor pos. sensor 1 is staying at 50% for some odd reason. Lambda is dropping close to 0volts at the exact same areas where I have the boost dropping. Now is the boost drops causing lambda to drop, or low lambda  (low fuel) is causing the boost to go safe? Here are the two logs where u can see this.

I labeled the variables correctly.