First we replaced the ignitor for the oven burner since that is what most of the problems seemed to be - no change. While testing I noticed that the burner would take what seemed like to me an unusually long time to turn off after lighting it manually. Also started to notice a faint gas smell when it was turned off that wasn't noticeable before. Suspected a faulty gas valve. Ordered the burner as well, because I didn't want to have to work on it again. Replaced both and after adjusting the flame size at the valve, the oven works better than it has in years. All in all, had about $150 and about 3 or 4 hours total in diagnosing and repairing the oven