To make a long story short my 2010 honda fit had been stalling when going uphill with a blinking check engine light. I see a code for the IAT sensor reading out of specification and the coolant sensor 2 reading high


-Spark Plugs replaced

-Coil packs replaced

-Fuel pump replaced

Ill be replacing both the IAT and coolant sensor but would either of those cause the stalling condition?


Thoughts? Comments? Any help is appreciated at this point

 

Since you just performed some services, do you think there's any chance there may be a vacuum leak that's semi-significant?
Uphill driving puts some extra demand on the engine and can highlight faults if any are present. 😬 and vacuum may not throw any codes, but your idle air temperature sensor may be picking up a legit issue with vacuum.

I always advise the checking of fluids (like trans fluid in this case, unless you've got a manual then just see if it's leakin') so I'd endorse that idea here too just to be safe. But yeah, I'd say check out the intake and if you've got time pop off the intake plenum atop the engine to verify that all hoses are connected.

Depending on your mileage you may be due for a new pcv valve too. While it may not be your fault, if it's working poorly it may add to a minor vacuum leak giving you a bigger problem.

I'm doing a PCV valve presently, so my head may be stuck on vacuum 😂

See it in there?

That and I put in spark plugs but didn't gap them. Dumb. Fixed that.


Edit: I forgot to add, do you have any issues with hard acceleration? I'd think if the issue was brought on by putting the engine under heavy load that hard accel would trigger it too. Otherwise I'd think transmission.. but that doesnt fit with the code you got.

 

Turns out one of the brand new coil packs failed completely today and finally set a misfire code.......

 

Gotcha, sorry to hear the bad news. I still don't see how that could pop the idle air temp code.. but if it resolves with a new coil pack be sure to update!

 

Ah. Good to know. Thank you for the follow-up.