Rep Power: 0

Hello Guys,
I've purchased a 2003 Honda Civic Ex with 97k miles a few weeks ago. The car is super mint. I picked it up from an elderly woman who had extensive maintenance history reports. Was driving perfectly for the few weeks I've owned it then last week after I got home from work I was sitting in my driveway with the car idling and it began to idle very rough and the check engine light started flashing. I figured it was a misfire from previous symptoms of cars I owned so I plugged in my OBD II and scanned the codes. It gave me the classic P0301 codes as well as multiple misfires. So the next morning I picked up some NGK iridium spark plugs and swapped them. Still misfiring swapped the coils as well and still was misfiring. So I just said F it and made an appointment at Honda Stealership because I didn't want to deal with it. They told me that it needed OEM spark plugs which were $150 and I knew that wasn't the case but I figured they may know more than me and just went ahead and approved it. So they changed the sparkplugs I picked up the car after spending $450 on their service and on the drive home it started to misfire again so I took it right back to the stealership. They checked coils, spark plugs, ran a compression test on it and everything came out to normal. Then they came back to me and told me that whoever was working on it before forgot to plug in the No. 1 fuel injector all the way and that's what was causing my misfire. So they drove it around a few miles and it never misfired or CEL came on. I figured that was BS but picked it up free of charge. Later that day I was on the freeway merging so I gave it some gas and boom CEl started flashing and the misfire was happening.

Getting annoyed and very frustrated about where this is coming from. If anyone can give me suggestions on similar issues they've had then it would help greatly. I read some stuff about possible worn-out spark plug boots under the valve cover but I'm not sure how they will cause a misfire.

 
Rep Power: 0

When you swapped the coils was it still mis-firing on #1 cylinder? If so, and everything else seems OK, you may have to pull the valve cover and check the valve springs for #1.

 
Rep Power: 0

Compression test.
Then, fuel injector test..
dc

 
Rep Power: 0

Oops, I missed where you said compression test was done. Another thing you can try is swap the fuel injector to another cylinder. See if the code moves to that cylinder.