2002 Honda Accord EX, L4-2254cc 2.3L SOHC (VTEC) MFI, 108,000 miles. Recently Bought it from a private owner and was told nothing was wrong with the car.
Car starts rough when the engine is cold. Sounds like its chocking. Giving it gas does the same, it chokes a few times and revs. It hesitates also when driving but only when engine is cold. Once the engine gets hot enough it drives like there's not a single thing wrong. Drove it out on the freeway once, car once fine until I got up to 70 mph, then car started to hesitate again. RPM wouldn't go past 3500 and the check engine light started flashing. I managed to get out the freeway and took the local road. The car drove like it had no problem. The next day I started the car the check engine was gone. I managed to get it checked before it went away and code was P1399.
All I've done so far is replace all 4 spark plugs (NGK) and distributor cap and rotor.
This hasn't solved the problem. I don't know much about to cars so if anyone knows about anything I would really appreciate the help.