07 A3 Multiple Misfires After Replacing All Injectors, Coils, Plugs

[jtruest]

I have an 07 A3 FSI with 128k miles that seemed to be running fine then I got a P0302 code, Cylinder 2 misfire. I tried swapping coils and still got the same misfire. I figured it was injectors so I dove in and removed the intake and replaced all 4 injectors with OEM Bosch, then I went ahead and replaced all 4 spark plugs and coil packs because those looked original. I also cleaned the carbon buildup in the intake. I also replaced the high pressure fuel pump because I was getting a leak at the brass connector.

Everything went back together fine, replaced intake manifold gasket, torqued everything to spec, and started up normally but it runs pretty rough. Engine shakes more than it should and it's obviously still misfiring. I get the flashing check engine light with a P0300 and P0301 code so it seems like there's a fuel delivery problem. I have a VCDS tool but I'm new to these FSI motors and don't know what to look for in the tool. It's almost like there's a previous tune on the ECM and the new injectors aren't playing nice but honestly, I have no idea now.

Any help would be greatly appreciated.

[Jhddr]

Damn, that’s frustrating after doing all that work. Since it’s misfiring on more than one cylinder now, I’d definitely check fuel trims in VCDS, see what block 032 says. Could still be a vacuum leak somewhere or something simple like a connector not fully seated. Maybe double check the injector plugs too, those can be finicky.

[Jhddr]

Also, depending on which Bosch injectors you used, some of them need to be coded or at least matched to the ECU. If the car had a tune before, that could be throwing it off too. These FSI motors can be touchy after major fuel system work. If you can post the VCDS readings, someone might spot something quick.