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Last edited by [email protected]; 09-20-2018 at 11:39 PM.
You aren't rich, you are extremely lean. Look at the fuel trims. If they are pegged at 25%, that means it's adding in 25% and your short term trims are staying positive as well. Negative numbers mean rich.
You are missing key data. You need to log both your front o2 sensors, your TPS, injector pulse width avg for both banks.
A wideband o2 sensor is a 100% must here, you can not properly tune this setup with out and you must figure out a way to include the wideband data into your logs. If you have the PRO interface it's easy, if you have the standard interface you will have to wire the wideband through the trucks EGR circuit on the computer and create a custom channel to log the wideband. Several threads and even youtube video's on how to set that up. Even a write in the VCM scanner section for creating an AFR/Lambda error against the commanded AFR/Lambda to fix the airflow model.
Lastly double check you have ZERO vacuum leaks and exhaust leak directly before or directly after the o2 sensors. Any leak will skew your readings and put you worse off.
Fair warning here as well, those stock injectors are really small on 1999's and you will likely max them out before you even finish your wide open throttle tuning. Hence the reason to log your injectors and watch the duty cycle, a 5.3 with cam/headers etc will put them over 100% easy.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
its adding fuel the entire time.. running lean accounts for the popping ... its not good to be doing so.. stft as much as 34%.. from what I see
What he said above me as well.... get an afr setup or learn to tune by the fuel trims
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