I have to replace the first O2 sensor in my 2005 Elantra GLS (Manufactured Sept 2004 if that made a difference). I'm trying to find out the correct aftermarket part and i think it's supposed to be a Bosch 17014 (that the LSU4.2 wide band sensor) but everywhere says it's a 4-wire (autozone, advanced auto parts, napa, and even bosch) but looking under the hood the sensor is definitely a 5-wire (going into a six pin "D" type connector.) Of course the dealers won't tell me anything since they want me to pay they're insane markup, one dealer said the part was 130 bucks and another said 165. yeah, advanced auto parts has the 17014 for 55 bucks. So in short is the 17014 LSU4.2 wideband o2 sensor compatible with the 2005 Elantra GLS engine? Thanks a bunch.

How many miles on your car? If less than 60,000, it should be covered under warranty!

It's over 60,000, it's out of warranty.

The reason the dealer is "not helping you" is because the dealer parts department has absolutely NO IDEA what aftermarket parts fit your car. I work in Hyundai parts and cannot tell you how many times customers get flat out furious with us because we cannot tell them if they can get certain parts aftermarket... It's not because they are trying to sell you the Hyundai part, it's simply because they do not know which Bosch part number fits your car, as Hyundai dealers do not sell Bosch parts, but only Hyundai parts.

I will tell you this much... aftermarket O2 sensors have been known to cause a lot of problems (besides not even knowing if it's the right part), such as check engine lights, and very short lifespans of the sensor itself. Is saving a little money worth the risk of having to go buy the Hyundai sensor anyway after it's all said and done?

Do yourself a favor and use the Hyundai parts. Aftermarket o2 sensors, spark plug wires, and nearly anything bosch almost always make the engine run like sh*t.

I would like to know how many o2 sensors are on the 2005 hyundai accent gls(i own one), because ive been thinking about putting aftermarket headers and exhaust on my accent. can anyone help? OH! and what size is the throttle body(mm)?

Without measuring, I wouldn't know the size of the TB, but your car has 2 O2 sensors. One is in the exhaust manifold, the other is further downstream in the exhaust pipe ahead of the second catalytic converter.