Accord 2018! 1.5T. My car shows cylinder 4 misfire. I changed spark plug and switch ignition coils with each other. But still it shows cylinder 4 misfire. Sometime When i cold start the engine in the morning time like car vibrate and stop accelerating. Can anybody help me!

 

How many miles on car? My 2018 had engine light come on, pulled codes :engine misfire. Cleared code. Runs great. ? I have 49,000 miles

 

Probably an air leak.

 

Dealer said change fuel injectors. Not. Car runs great.

 

the reason for the dealer saying to change the injectors is because one or more of them likely failed the cylinder A/F test. Have seen this on numerous occasions. It will eventually get worse and likely set a P0420 code. But that doesn't mean the cat is bad, it just means the bad injector is being leaned out to the point that it over-leans the others. My suggestion is to do the injectors or it can cause more harm than good.

 

if it's not losing coolant, it's probably the injector. I had same issue and was told by stealership it was head gasket. I changed head gasket, but still had same symptoms you described. I changed the 4 injectors w/OEM and it's been running like new since (25k mi).
If you are a DIY person, it's not too bad of a replacement, about $400 in parts, and about 4-6 hrs of newbie time. Make sure to watch several utubes on it before attempting, there are some good tips out there.
They recommend replacing gas tube between injector rail and high pressure pump but I didn't and it sealed as well as original. Take your time and line up the j-tube before applying torque.