NJ_phil

First drive of the season after installing dual WB shows passenger AFR running a full point leaner than the driver's side.
Both STFT and LTFT run the same for both banks and both WBs track evenly in CL and only runs lean during PE.

Running a 58psi return system with a AEM-380 secondary pump which I can see kick on at 3psi of boost, about 780hp.
Stock fuel rail with crossover tube, fed from the stock driver's
side.

Suspected the passenger side rail might be getting starved for fuel but second guessing that because the variation shows immediately when dropping into PE even with injectors running only at 20% DC. Going to pull the plugs tomorrow for a look.

Looking for some advice.

Thanks

tblu92

Most often source on a mis match between left/right is an exhaust leak even a small one will make the WB readings not match

NJ_phil

Turns out it was a bad sensor. Pretty much dead on now.

TurboLX

Correct, 99% of the time this ends up being a problem with the wideband itself. Cheaper units do this all the time, either the sensor, wiring, ground, or just controller variation at high temp and rich conditions. This is why I only use ECM lab grade widebands for my work and recommend the AFX/AFR500/AFM^2 for consumers because they're made by ECM.

Another quick check here would be to verify delivered pulsewidth on both banks. If they're both the same, and your injectors are a matched set, chances are that you are delivering the same fuel everywhere and the problem is somewhere else. This was your case, and it makes perfect sense.

NJ_phil

I'm pretty happy with the Bosch LS4.9s and AEM-0333 gauges which should allow me to get a heads up on a problem with either an injector or plug, at least narrow it down to which bank.

The best part is I left a lot of power on the table pulling spark because AFR was in the 13s while I thought it was high 11s. Surprised things held together at 14psi/13.2AFR/10* going through the traps at 135 mph.

handyandy1496

Just swap the wideband sensors.