01-22-2019, 04:33 PM
Join Date: Mar 2018
Location: Reno, NV
What I Drive: 2011 Focus SES
FF Reputation: 1
Buy-Sell-Trade Rating: (0
Mine is doing the same thing, except mine seems worse than yours is. I still haven't replaced my o2 sensors or EGR valve yet, which may be causing the issue. However, I am 100% sure in my instance that I have a vacuum leak (possibly multiple) due to being able to hear hissing coming from the engine every so often.
Here's a list of things I know that will make it idle worse:
- Turning on the AC
- Turning on the defroster
- Switching from park to drive will temporarily cause an upset (assuming this puts more load on the engine)
- When it's colder outside (20 F or so)
I am taking it to a shop to have someone more knowledgeable than me look at it on Thursday. I don't have a CEL yet.