Hello, Scotty. My 2012 Honda Civic automatic with 73000 miles has been having sluggish acceleration/hesitation for awhile now and is driving me crazy. Just to compare, my brother and a buddy of mine own Civics of this generation with a similar amount miles that do not have this issue. My Civic has been regularly maintained.
I tried doing a couple of things such as cleaning MAF sensor, MAP sensor, EGR valve, and replacing the pcv valve. I also cleaned my throttle body, but nothing seems to fix the issue.
This issue mostly occurs when the engine is warm, the acceleration is fine on a cold engine. This hesitation is most apparent in the 2000 to 3000 rpm range.
I scanned my Civic with a scan tool and there were no active or stored codes, but I did notice my fuel trims are close to -10%.
Have you checked the air and fuel filters? Either of those could be the culprit of they are clogged up.
If those are ok, I'd run a bottle of fuel injector cleaner through the tank and see if that helps.
Do you have access to live data?
The live data suggestion is a good one. Possible causes for this negative fuel trim:
The fuel injectors are clogged/dirty
The fuel pump is going bad
The fuel filter is dirty (if you buy non-Top Tier gas, this is more likely)
There's a malfunctioning fuel regulator.
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Get a diagnosis before throwing any parts at it. Scotty has a video on cleaning fuel injectors, professionally.
https://www.youtube.com/watch?v=bKGI9N_yWd0
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