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?

[Vettywhite]

My 2022 zl1 is doing the exact same thing, I just installed Magnuson 2650, DSX aux pump as well. Goes into limp mode and sputters on acceleration, high side drops to zero and recovers. What did it end up being the issue for you? I'm hearing it's the high pressure fuel pump that is going bad.

[22 LTX]

I got this too, the HPFP makes sense.

Although it may also be the fuel lines collapsing/reducing in cross section under the suction stroke, this would lead to cavitation and would also damage the pump.

I will repost when I take mine off and comment on what I find.

Question, are you getting fuel in your oil? Pretty sure that happening to mine. Oil goes brown after a 100 miles and got some vapour coming out the oil filler