I couldn't find my make and model above, so I selected Hyundai Accent. Actually, my car is a 2002 Daewoo Lanos, 1.6 L 4 Cylinder. The car dealer that sold me the car, told me that the engine is made by Hyundai, and the body and chassis is made by Daewoo. That's why I selected Hyundai. 4 scan codes that were found : P0300, random multiple cylinder misfire detected P0128, coolant temperature below thermostat regulating temperature. P0141, oxygen sensor heater circuit malfunction P0341, camshaft position sensor A Bank 1, CKT range/performance One of my neighbors and I have seemed to agree on a few things. The sluggish engine performance ( misfiring ) is because of poor compression, and the poor, or low compression is present, because the seals, gaskets and o rings were blown out because of the overfilling with oil. Does anyone here think that that's a good guess ? Does anyone think that a compression test would be worthwhile ? Should the gaskets, seals and o rings all be replaced with new ones ? What about spark plug wires ? I'm at 95,000, and they've never been changed. I'm definitely going to get new spark plug wires, water pump and timing belt. Finally, does anyone out there know if there are more than one oxygen sensor in the car ? I've heard people tell me that there is definitely one in the emission control system. In any case, if there is more than one, should I just replace them all ? l. Short history of problems a. Hard to start, sometimes taking up to 30 or 40 turns of the key, and sometimes it starts up and fires on the first key turn, and when it does finally start it runs sluggish. I don't have a problem driving the car downhill, but going uphill, it starts to sputter and slows to a stop. I don't hear noises like pinging, chattering or scraping of metal engine parts, just a chugging sound, so I'm assuming that I don't have major internal engine problems. b. Before the problem with the ignition switch and sluggish performance, the only other problem I was having with the engine sound was that when the engine was warmed up, and I was driving through town, and idled the motor at an intersection, I noticed that the rpms would change, sounding erratic, higher in volume, as in amplitude. This was an intermittent problem. It would come and go. c. The shifting of gears ( it's an automatic ) is slightly rough, but it doesn't make a clucnking or thudding sound. I've never changed the transmission fluid, because my Daewoo repair manuel ( that I got online, from Daewoo ) says that there's no way to change it, no filler cap or drain plug. d. Two or three times, since 2004, the cooling system has overheated, but not to the point that I developed major engine damage. My radiator has a slight leak, but I don't think that overheating is an issue with the scan codes. Maybe I'm wrong about that. 2. Past mistakes I have made that may have led to these problems. a. I don't know what's causing the problem with the ignition switch, maybe it just dirty, corroded or worn out. Maybe there's something in the scan code that will tell me, I don't know. b. A couple of times, in the past year, I overfilled my engine with oil, and that's when I started to get sluggish engine performance, when I was climbing hills or steep grades. I told some of my neighbors about this problem, and one of them told me to change my oil and sparkplugs, which I did, and the car started running a lot better, normally, but I was still getting the engine logo light on my dashboard, and the ignition switch problem, and the erratic idling at intersections. Then I overfilled the engine again, and the sluggish performance came back, but this time it is running so badly, that I'm afraid to drive it, fearing that I might develop major engine damage. I changed the oil again and bought new spark plugs, thinking that it would run better, but this time it didn't. c. A couple of years ago, I was coasting downhill in neutral, trying to save gas, and I started going to fast around the curves, so I tried to shift it into drive, but I made a mistake, and shifted into reverse, but oddly, I didn't hear the gears grind, the engine stopped, and then I pulled over on the side of the road, restarted the motor, and drove off, and the gears shifted OK. Maybe there's a safety shutoff mechanism. I do shift gears a lot, to save on the wear and tear on my brakes, because they're getting pretty thin. This may be why my shifting is slightly rough. The scan codes might help me find the problem, we'll see.
Scan codes , what they mean, history of problems, and past mistakes on 2002 Hyundai Accent
by H.T. Oliver in Guatay, CA on April 24, 2011
ANSWER by torque wrench on April 24, 2011
I would start with checking the timing, and play in the timing belt or loose tensioner. If that checks out ok, I would replace the cam/crank sensor. If it is sending bad information to the computer, it is advancing or retarding the timing and air/fuel to the point of poor running. If the timing proves to be off you will get false results on your compression test. Be sure timing is correct, and you can do one to get results of other engine components like head gaskets. But remember timing off will result in engine overheating too. heated circuit in the oxygen sensor being bad, will result in a lean or rich running engine. I would go ahead and replace the O2 sensor, and with the mileage and driving condition the timing components too. Coolent temp below temp tells me you need to check coolent level, probably low and sensor can't read temp. or the sensor is bad. I would start there and see how things go before buying anything else at this point.