P0300 / Tuning Mystery
Need a little help on this. Primarily rough idle and occasional surging to light throttle issue, sets the P0300 code even after increasing values in C5621. No expert but, looking at the log, seems like something is up with the O2 sensor system.
6.0L in a Yukon XL, small cam (-2 degree overlap), 823 heads, TBSS intake, SEP injectors (with their tune data), stock exhaust...
To this point:
- New MAF and front O2 sensors
- New plugs and wires, good spark, plugs look good/all the same
- Noid light check on injectors
- Good compression
- Smoke check - no apparent vacuum leak
- I've reduced the idle spark overspeed/underspeed compensation B5935/6
- Desired Airflow, VE, and MAF frequency are as close as I can get them
Check the crazy voltage readings on the O2 sensors (WB at location 11). I figure it's normal for the WB to read about 450mv steady?
I've suppressed the secondary 02 sensor DTCs and figure the CATs have lost effectiveness but the performance is so good, it doesn't seem like they could be clogged.
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