2010 titan rpm went idea goes down then back up?

Could be as simple as a clogged engine air intake filter. Or more likely a faulty idle air control valve. If you have drive-by-wire (what a stupid name for a process) it could be a problem with the computer reading defective sensors, like the engine coolant temperature sensor. Or it might be a vacuum leak or something causing a misfire, and that might be why the CEL is shining in your face.

Could be as simple as a clogged engine air intake filter. Or more likely a faulty idle air control valve. If you have drive-by-wire, it could be a problem with the computer reading defective sensors, like the engine coolant temperature sensor. Or it might be a vacuum leak or something causing a misfire, and that might be why the CEL is shining in your face.

REALLY TIRED OF N.O. P.O.S.T. ON WEEKENDS.

Sounds like a c coil pack

Get the code. Could be a bad ISC.

WEEKENDS? I get it after about the third question, any day of the week, especially bad if it use IOS and not windows.