I recently bought a 2002 Accord LX. Which we've discovered has an 03 engine (we think cause the oil filter was for an 03). So far we've changed the oil filter, air filter, spark plugs, plug wires and rotor.

However, whenever I first start it, day or night it run "shaky" like it's going to kill or stall, and feels like it's slipping. The check engine light blinks.

If I restart it, it seems to work okay and when we put a reader on it all that comes up is P1399 which we clear and it works okay, until again I cold start it.

Any idea what else we can fix to stop this?

btw it's a vtec 4 cil engine

 

I've brought it to a dealer, and they cleaned everything. Can these things come on from a fuel injection problem? No one can seem to tell me what's wrong.