Ext Temp Sensor and Service Engine Soon

[wuiseng]

hi...i am new to new forum. i have been driving a buiclk regal ls 2000 for close to 2 years. i have some questions here.
1. the ext temp sensor doesn't seem to work. for example, the temperature this morning was in the 40s, but the indicator panel showed 105 F at the start and reached 120 F within 15 minutes of driving on the highway. i have read that this could be due to a faulty sensor, and the best way would be to replace with a new one. Is it expensive to get a new one, or can i drive my car and ignore the temperature indication? there was once the ext temp sensor indicated a very high temperature, and the engine would not restart. i had to wait for a while before the engine could be started. i don't know if engine problem is related to the temp sensor.

2. the Service Engine Soon light came off recently and lasted for a couple of weeks. A few days ago, for some unknown reasons, the light went off. is this a common issue in buick regals? should i ignore it since the warning light has gone off?

thank you. hope to hear some feedback.

[BNaylor]

The external temperature sensor problem and SES light sound coincidental. It sounds like the ext temperature sensor is bad. It's located in front of the radiator on the support bar and is easy to replace.

On the SES light get it obd-ii scanned when it comes back on again. Getting a SES Mil light is not normal and indicates an emissions, chassis, abs or tranny fault. Unless you have driveability problems, you should wait until the light comes back on. Places like Autozone will scan for free but only if the SES light is illuminated.

Welcome to our humble forum.