I have a 2006 Kia Rio. Recently the CEL did not go off. It ran fine. My Actron said all monitors ready and a P0304 code. I removed the battery cable to clear the computer. The battery was leaking so I replaced it. The car ran fine and about two days later the CEL came on again. It still ran fine. The Actron said P0302 this time, all monitors ready. I drove it for a day and it started running rough at low RPM and the CEL began blinking. Actron now said P0300, 301, 302. I replaced the plugs and checked the coils. Yes, the coils are a little out of tolerance but they are all reading the same. It wouldn't be the first time I put a vehicle back together with non-perfect parts. I have replaced the air filter, cleaned the throttle body and PCV. I have replaced the hoses from the valve cover to the throttle body and to the air intake. It runs better. The CEL comes on after a few seconds and blinks. If this was my old GMC, I would stick a timing light on all the wires to indicate spark, then adjust the carb. I have checked the new plugs and they all seem to be firing. A bad fuel filter, dirty gas or maybe the pressure regulator, or pump might cause this or an injector. I haven't checked the injector resistance but a good injector may still spit bad or insufficient gas due to other components. I really don't think it's a big problem I'm just trying to pin-point it. I understand what the P Codes are saying but that's like trying to find a miss on a 350 chevy. It could be several things. I don't have the attachment to test the fuel pressure. While it's depressurized I'd like to take out the injectors and look at them. I'm tryting to run down the easy stuff before taking it back to those knuckleheads at the local Kia. Currently the Actron says Comp, Fuel, Misfire 'Ready' and P0300, P0302 and P0302pd codes. That's the story from the start.
Thursday, January 3rd, 2013 AT 5:16 PM