I was driving on the highway and began accelerating. The car was about 50-60mph and RPM was 3-4K and then suddenly went into limp mode. Felt like a shutter and then in limp mode was not able to go past 20mph. Pull off the highway, shut off car and restarted to clear the limp mode but what is the issue? I didn't feel any battery issues prior.
2009 Honda Accord Lx 2.4
Found the problem, spark plugs. Very apparent when I removed #4. Changed the OEM ones about 2 years ago with what I thought were another set of genuine Honda plugs. However, I have my doubts now since I purchased from eBay.
Scanned codes - P0304 - cylinder 4 misfire
You need to investigate why that cylinder is misfiring. Could be a bad coil or bad spark plug, electrical wiring problem, bad fuel injector, or something more serious like that cylinder losing compression due to mechanical failure.
Found the problem, spark plugs. Very apparent when I removed #4. Changed the OEM ones about 2 years ago with what I thought were another set of genuine Honda plugs. However, I have my doubts now since I purchased from eBay.
Thanks for the followup, this is an example of why Scotty always says to check the simplest and least expensive things first.
NEVER buy critical parts from eBay. Even Amazon is risky, with their army of small sellers shipping out of their basements it's really not much better than eBay. I buy parts either locally or from online auto parts specialists that are known to be reliable.
Yes, found that all spark plugs were toast! 2mm+ gap on all 4 plugs.
Other note, Honda makes some great engines. Never even noticed any performance issues until this week, still got 26mpg.
You haven't provided the mileage.
Have you scanned it for codes?
Also check this out, perhaps it helps:
https://www.mrtyre.com/help-and-advice/limp-mode-causes-and-what-to-do-about-it/
167000 no codes, engine light was flashing
Scanned codes - P0304 - cylinder 4 misfire
Scanned codes - P0304 - cylinder 4 misfire