'13 Focus St spark oscillation issue

[Raddtadd]

I'm trying to fix some driveability issues on a 13 ford focus st. Its got a handful of unknown mods and so we're kinda guessing and doing the best we can.

Under light throttle and lower rpm's the car will stop accelerating cleanly and you can hear the exhaust note change and start oscillating. If your looking at the logger you can see the spark advance jump up and down roughly 30 degree spreads. This is the first DI ford ecoboost I've dealt with so I'm not sure if there's something I have overlooked.

Car has aftermarket cobb intake, upgraded map sensor, full exhaust, upgraded externally gated turbo, fmic, pipes, bov and whatever else I can't tell.

Any insight or help is much appreciated.

[Exley]

http://www.focusst.org/forum/focus-s...misfire-4.html

Does that sound similar to what you are experiencing? There's no real answer in the thread, but I was following it since my car does the same thing. Thought it was a misfire the first time I noticed it. My car is bone stock other than a green filter and small changes i have made with HP Tuners. 13 Focus ST as well.

[Raddtadd]

It does except it does it warm or cold and definitely isn't a misfire. Did yours do it before you made any ecu changes???

[Exley]

It does except it does it warm or cold and definitely isn't a misfire. Did yours do it before you made any ecu changes???

Mine will do it warm or cold. It seems to be when there is higher humidity. I can't tell you for sure if it did it stock. If it is something in the tune it would be a side effect, I haven't touched the spark tables.