2019 CTS V P228C and P0089

[doc350]

I just finished installing some mods on a 2019 CTS V, and when I took it for a drive, it threw a P228C and a P0089 and went into limp mode.

Here are the mods

Headers w/o cats
2.3 Upper Pulley
8.6 Lower Pulley
Snow Dual Nozzle Meth Kit
DSX Aux Fuel System
DSX Flex Fuel Kit
Pro Speed Heat Exchanger

When I cruise the car through the gears on the dyno, I can watch fuel rail pressure drop almost to zero and the it throws the codes. I flashed the stock tune back in, minus the fes fuel settings, and it still did it, so I don't think it's anything I did tune-wise.

Has anyone else come across this? I've done other cars with similar mods, but never ran across this problem before. I attached the log of it doing it below.

fuel pressure drop.hpl

[doc350]

Also, car has e70 in the tank right now.

[HeavyChevy305]

Also, car has e70 in the tank right now.

Stock air box? You're running out of fuel. Try bringing it down to e30.

[sevinn]

Has the hpfp ever been off the car?

[doc350]

Stock air box? You're running out of fuel. Try bringing it down to e30.

Yes, stock airbox. the problem happens at cruise. If you look at the log I posted, fuel pressure drops from ~1400psi down to ~5psi and then eventually comes back up, but by then the car is in limp mode.

Has the hpfp ever been off the car?

Nope. I pulled the blower off to change the pulley, but I never touched the high side fuel system.

[Higgs Boson]

post a pic of your VVE table

[doc350]

I haven't even started to adjust it. The car goes into limp mode before I can do any real driving.

[lsxrx7]

Any updates on this problem?