I'm beginning to think my car's issue relates to a sensor, either that or maybe the ignition module I replaced is going bad, as really the car seems to have hesitation/stumbling once it's started to warm up and really right before the O2 sensor comes on and compensates. Anyway I'm wondering, when the car is in Open loop what does it use? Just the AFM or in my case the MAF and the ECU's pre-determined fuel maps? Does the car use the CHTS? I know it doesn't use the O2 sensor in open loop. I'm thinking it's gotta be some sensor possibly such as the CHTS making the car run too rich or lean before the O2 starts compensating.