Running Lean

[91LS1S10]

Just got my ls1 Chevy S-10 running and trying out my Efilive software. Went for a drive on the freeway going downhill and noticed that my LC-1 wideband was showing 20.0. I also noticed that the spark, long term fuel trims and injector duty cycle was all at zero. Is that normal? Would appreciate any input.

Rey

[SSpdDmon]

Sounds like you were in DFCO. When you let off the gas and manifold vacuum is high enough (aka MAP is low enough), the PCM will command DFCO (deceleration fuel cut off). The spark will then drop to 0~6 degrees and fueling is cut. When you were on the gas, the timing and injector duty cycle looked normal, right?

[91LS1S10]

Once I get back on the gas everything looks normal. I also checked on my 2000 silverado and it does the same. Thanks for the info. I'm new to this and still learning.