I have a 2001 kia rio, check engine light came on. stopped at Auto Zone an they tested it. Their machine said it was CODE P1166. what is this part we need?

PO 102 MASS AIR FLOW SENSOR CIRCUIT LOW INPUT, I NEED MAKE MODEL AND ENGINE SIZE AND I CAN BETTER HELP YOU BEEN ON KIAS SINCE 98 MASTER CERT.

go to Auto Zone or Checker Auto and they can run a test to see what is causing the problem

P1166 refer to O2 sensor heater circuits malfunction, HO2 Heater system electrical, bank 1.

take to an auto store most such as auto zone / advanced auto offer the scan for free the code will narrow down where the problem is so u can repair the car

Could be a transmission problem, or other fault. Best recommendation I can give you is get the Haynes repair manual for your vehicle and if an Auto Zone is close get them to read the fault code for you. That will tell you what the problem is and give you an idea if it's something you can fix.

need to have the car scanned for the trouble code some auto stores such as auto zone / advanced auto scan for free check ur local area the trouble code will give u a start point towards solving ur problem

there can still can be a problem some auto parts store can test the car with a computer for free and the you what it is. it can be a loose gas cap or a sensor. e.t.c

Go to a auto parts store like Kragen/Napa/Chief's/Pep Boys/Auto Zone and have the codes read. Your car's "brain" is trying to tell you something.

Those places will read it for free by the way.

try your crank shaft sensor, sounds like the same problem i had , had crank shaft sensor replaced and it drove fine afterwards. maybe go to auto zone or something and see if that code comes up

There are over 100 things (and yes the gas cap is one) that will turn on a CEL, run a trouble code test, Kragen and Auto Zone do it for free as well as other chain stores like them.