Check out my log, got a couple questions

[Mitsu_Racing]

Ok after a couple logs and a little tuning this it what i got. I'm not done i know i have to richen it up on the higher RPM's. My first question is the logs i highlighted in orange, i'm running very lean, do i richen it on the HI throttle or the Lo trottle? Secondly in the red, what would cause my O2's do drop so suddenly? Around those RPMs i hear pops come from the exhaust and the car suddenly jerks.

RPM	Timing	Airflow	02 Bank 1
    1956	19	3.16	0.92
2020	5	5.12	0.78
2004	4	5.33	0.98
2064	4	5.47	0.98
2160	3	6.01	0.98
2252	3	6.49	0.98
2340	3	7.08	0.98
2428	3	7.6	0.98
2512	3	8.23	0.98
2628	3	9.09	0.98
2748	3	10.05	0.98
2900	3	11.2	0.98
3032	3	12.78	0.98
3196	2	15.09	0.98
3428	3	18.38	0.98
3604	3	21.92	0.96
    3892	3	25.4	0.62
4104	4	24.02	0.96
4360	5	28.7	0.96
    4596	6	18.45	0.48
4768	7	30.85	0.96
4972	9	34.13	0.94
5052	10	30.83	0.96
5376	9	35.99	0.94
    5540	10	37.52	0.24
5384	11	35.62	0.94
5824	11	38.11	0.92
5980	10	26.5	0.88
5960	13	37.72	0.92
6220	14	39.16	0.92
6420	14	36.42	0.92
6540	14	39.61	0.9
6324	15	35.54	0.92
6796	14	19.47	0.62

[GVR4592]

Airflow seems to be a little quirky in those red area's as well. What injectors are you using and what are your safc corrrection settings? What turbo are you using and how much boost? The pop from the exhaust and jerking can be caused by a lot of different things. I would check the spark plugs and spark plug wires, boost leaks, and leaks between the turbo and maf sensor. What is your base timing?

I wouldn't worry about the orange area too much, the turbo isn't really making much boost at that rpm and you could get away with running a/f in the 13.5-14.5:1 range without trouble. If anything it's going to help spool the turbo a little quicker. If you do feel like richening it up you would do it on the Hi Throttle map, as long as that run was at WOT from the beginning. Don't tune by O2 voltage, just shoot for timing advance.

Usually when an O2 sensor gives readings like that it's a sign that it's failing. However if the car is jerking and popping from the exhaust in those same area's it's most likely not the sensor.

[Mitsu_Racing]

Corrections

1000 3
2000 2
2600 -9
3000 -11
3600 -11
4000 -9
4600 0
5000 6
5600 13
6000 14
6600 14
7200 13

I have RC 550's, small 16G @ 15 psi. My base timing is set at stock so i guess 0. Thanks.