[mucleman21]

2018 zl1 with ported blower/snout , TSP cam, 2.3 upper, 5" intake, 103 TB, and 2" header back 3" exhaust, MM Catch Can, Low side pump, running 93.

I'm lost and running out of troubleshooting options. According to my VCM Scanner logs, my STFT 1/2 are 10% apart. seems like I have a vacuum leak of some sort on my bank one.. I've done a leak test by spraying break cleaning along the base of the blower, valve cover, catch can tubes, exhaust manifolds, and pvc lines. I've also cleaned my O2 and wideband sensors, I have 0 leaks coming from my exhaust.

[Gunkk]

Your injector timings all not the same. Your averages are 13% different between banks. So it's commanding 13% more fuel on bank 1. Why? (rhetorical) Is it your wideband sensors or something else?

Looks like you've already done some air leak chasing, but did you do a positive pressure smoke test?

Did you also swap the O2 sensors to see if they're the problem... and did the readings move with the sensors? Are the voltage trends on the sensors the same?

Are all your injectors working properly? Swap injectors side to side.

Spark? Any off color plugs? If you swap all the plugs side to side does the problem go with? Then swap coils.

Compression?

[mucleman21]

Yes i swap O2s, coil packs, plug wires, and new spark plugs.

Positive test only allowed smoke to come out the baffle on the catch can.

The voltage aren’t equal but the both goes up and down to the same numbers.

Haven’t done a compression test yet.

[Megahurtz]

Have you checked the gaskets between the headers and the heads on the engine? (manifold gaskets)

Small leaks here can cause this.

[Evansa22]

Having a similar issue. Was told its a leak pre o2 or right after which is letting air in and causing similar readings. Might need to reseat the exhaust manifold gasket, that's the next thing I'm gonna try

[KingLT1]

Originally Posted by Megahurtz

Have you checked the gaskets between the headers and the heads on the engine? (manifold gaskets)

Small leaks here can cause this.

This.