my water pump just went out on my 2012 v6 Mustang. it is now idling badly, it will rev up to 2K and then drop to 800 (normal) any ideas what to check so i dont have to take it back to the dealership?

vacuum lines

Try taking battery loose,for a few minute,s may reset,make sure key is removed form igintion when you do this,if it don,t fix the issue,check the tps.

Agree with crumbob,that is possible,they did remove part,s on the engine,good call crumbob.

when you take you battery out crak your engine til it stop totally to geet all the electricity out of the system and leave it over night

did you leave your Mass air flow sensor on? since you put the cold air intake on it?most kept it on. if so, take it off and clean it with air flow sensor cleaner, you can get a can at any, auto parts store,,, that is why it's idling so rough,it mite have to be replaced...if it's bad. a good cleaning usually helps. now if you didn't keep it on when you put the cold air pipe on. then it not plug into anything, and your engine will run erratic......hope this hope

Yes, the mass air flow sensor is on.. i have had it on since installing the system several months ago.. but i will take your advice and clean it. i have disconnected the battery, and let it sit disconnected. it didnt help, though the max rpm's on the engine are 1800 now. however, at least it only drops to 800 or so and doesnt act like it will stall out.

Buy a can of cleaner and when you take the unit off some of them have that funky torx's drive with the hole in the middle,but other then that, it will help, and also check the air senor, that threads into your exhaust system, eather on or before the cat. converter, it just screws right out with a 13mm wrench, just bee careful not to twist the two wires coming out of it...hope this helps