2000 Sephia O2 sensor problem

I have replaced the No. 1 O2 sensor with a new Bosch sensor purchased at a local Advance Auto store. So far the car has burned up two new sensors. They only last about 30 minutes of driving time. My fuel milage has dropped from 35 mpg to 24 mpg. The altenator, battery, air filter, and spark plugs have been replaced. The check engine light is still on and the car computer is giving the O2 sensor trouble codes. The local KIA service manager told me I MUST use official KIA parts in order for this problem to be resolved. The official KIA O2 sensor is $120 higher than the Bosch sensor. Do I need the official part or am I being mislead?

Reply to
sephiadriver
Loading thread data ...

What is the full OBD-II code or codes you are getting? Another thing to keep in mind is that a trouble code indicates a problem with a CIRCUIT, not necessarily a sensor. It's very unlikely that you are 'burning up' o2 sensors with 30 minutes of driving. If I had to hazard a guess I would say you have a problem with the connector(corrosion/broken wire, melted wire, etc) or possibly a bad ground.

Post the codes here and tell us which year of car you have and the engine size. The part about using 'official' Kia oxygen sensors is not true. Kia does not make O2 sensors, the original equipment was probably manufactured by either denso or bosch.

Chris

Reply to
halatos

Chris, P0131 - O2 Sensor, Circuit Low Volts, Bank 1, Sensor 1. P0135 - O2 Sensor Heater, Circuit Malfuntion, Bank 1, Sensor 1. This is a 2000 Kia Sephia with the 1.8 liter engine. For a little history on this car I purchased it last month with 47,000 miles on it. It drove home fine and averaged 35 miles to the gallon. Within two days the bearing in the alternator went out and I replaced it with a rebuilt one. The belts would not stay tight and the car ended up draining the battery while running and then died. I replaced the battery and retightened the belts. That is when the check engine light started coming on. I then went to Advance Auto and had them put the OBDII on the car. That is when the fun of lower mileage and purchasing and replacing sensors began. I have also replaced the negative ground wire on the battery which helped the grounding. I went ahead and purchased the original sensor. OUCH! The car does seem to run better, however the mileage is still at 25 mpg. I will check the connections. What else can I do?

Reply to
sephiadriver

Did you buy a universal O2 sensor and wire it up yourself or did it come with a plug that matched the one on the car? It sounds to me like the O2 sensor had the heater and sense wires in the wrong positions.

Chris

Reply to
halatos

The sensor is a factory original equipment replacement. The plug end came pre-assembled and it will only plug in one way. I can not find a broken or melted wire unless it is hidden within the wiring harness.

Reply to
sephiadriver

Yes, but sometimes the aftermarket replacements will have the same plug but the wires may be in the wrong positions. Case in point, the 30 amp relays that kia uses on the sephias look identical to a standard 4 prong relay from the outside, but the kia relays are rotated 90 degrees internally. The aftermarket relay will fit, but it will not work unless you take the fuse panel out and reposition the wires to match the aftermarket equipment. A similar thing happened to me with a blower motor replacement on my mitsubishi pickup. I got it all installed and wired up..and the damn thing ran backwards. Had to reverse the wires to fix it.

Regardless, if the engine light is off now that's what matters for your current situation. You will need to run a full tank through the car to accurately gauge your fuel economy, however. You need to start with a full tank and either reset the trip odometer or write down the mileage. Drive until the gauge is on E and then fill it back up.

At that point either take the trip odo reading or the new mileage minus the start mileage to compute how far you have gone. Your gas receipt should show how many gallons it took to fill the tank back up. Now you know how many miles you traveled, and how much fuel it took to get you that far. Computing the miles per gallon is simple division. Let us know how it turns out...

Chris

Reply to
halatos

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.