[ischmitz]

Tippy, I responded to your PM. Let me just touch some points here:

You need to check your mixture (don't mess with the adjustments without having proper test equipment). If it is out find the reason for it. The chip is an unknown as others pointed out. However most chip tuners only mess with WOT maps so it not the likely root cause. But to be sure you either need to read it and compare it to stock or swap it out to a stock one.

If you are too rich, you could have leaking injectors, bad fuel pressure, or an open CHT, or a bad DME (sensor input damaged)

One thing many overlook is the fuel pressure regulator. If the vacuum line to it is damaged or the regulator is blown you might run at max. fuel pressure resulting in a rich condition at part throttle. As a quick test pull the vacuum line with the engine idling. It should make a difference (go rich). If not you have an issue with the FPR.

Hope that helps,
Ingo