When I bought my car it didn't have a thermstat installed. This weekend my waterpump was replaced and when I picked up the car it was running bad. It was missing choking to stay at a idle. I was wondering if a thermostat was installed would it cause this to happen, since it was running perfectly fine before replacing the waterpump. The shop owner told me to bring it in on Monday that it was the Air Flow sensor assembly that was the cause.My question from the 733i experts is by changing the waterpump and installing a thermostat would this tie in to a problem with the air flow sensor since my thermostat was off when I bought my 733i.I am not sure how the thermostat and air flow are tied in or are they. The car does run better as it warms up but if you try to restart it even if it was running I have the problem of it choking itself to death. Any help would be appreciated.