I've thrown CEL's telling me the coolant temp sensor at the bottom of the radiator is on the fritz. I've read one post suggesting that if one leaves the coolant reservoir cap on, the vacuum prevents a large amount of coolant from escaping once the sensor is removed. Just trying to gauge how easy this would be to do myself. Stealership wants $160! Anyhow, it'd be great if I can get away without replacing the coolant (and disposing of it and bleeding the air etc) TIA...Jeff