Problems with low coolant light

I keep getting a low coolant light when I drive the car. I have checked my coolant level everytime and it is fine. Anybody know how to fix this? I can't find the part nu,ber for a collant level sensor. Thanks

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'98 Silver Z28
Whisper Lid, MAC headers, Custom H-pipe/Dual exhaust, Free mods, BMR Strut brace

yep it is the sensor mine did the same thing expecialy when cold.i think the sensor number is(1 10096163)it costs around $53.00,hope this helps.

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99 Camaro Z28
LS1 A4 30,000 miles
flow-pro exhaust