I recently had an error code about mine and haven't replaced it yet. When I tested it (from Chilton's) the MIL light did blink constantly when I held the gas at 2k rpm's.

1. Would this affect my gas mileage?
2. Is it really over $100 for the part?
3. Do I really need to replace it?

 

1. Yes, if the check engine light is on, your engine will run rich, basically wasting gas, to protect the engine.

2. It will be around 60-70 from courtesy nissan. The rear O2 is the expensive one.

3. You can try resetting the ECU and hope the light doesn't come back on. I drove on 3 shot sensors for nearly 6 months. It can be bad for things like the fuel injectors in the long run since they will be spraying heavy.

 

It's been about 2 weeks or so and the MIL hasn't come back on. I guess I'll go ahead and change it, though Courtesy is only offering the Front O2 Sensor for $117.

 

You can get a Bosch sensor through Autozone for $78, and for a small deposit, they will let you take a socket that fits the sensor which you can change yourself in about 20 minutes.

 

I wouldn,t get it from them then. Did you tell them you are from the .org? Go with autozone or whatever like iwannabimmer says.

And if the lights back not on, then it no hurry to replace it. You only waste gas when the lights on.

 

So do you have any idea why i would get the 0413 error and then it would go away like that?

 

I made it a week or two here and there, and eventually I couldn't make it out of the diveway. I got so sick of resetting the ECU I finally bought them, but I got a new Y pipe to inspire me a bit .

 

I don't think they always just fail at once. If it's starting to fail, and work within limits sometimes and not others, you'd get an intermittent code. Eventually, like Brigboy said, it just won't work at all.

 

The 1999 and 2K+ O2 sensor are more expensive than other years of 4th gen. The best price I found was $112. I replaced two so far. One was faulty and the other one I replaced by mistake. Read the FSM wrong

 

you can get a universal bosch o2 sensor for about 40 bucks.. the only thing that makes it universal is that it doesnt come with a plug on the end of the wires, you have to cut and splice into the existing plug with butt connectors that are provided.

 

Actually, the front O2 sensors is more expensive than the one mounted behind the cat. As for the type of sensor, I could not find an O2 sensor at the local Kragen for less than $140, so I just purchased one from Courtesy for $109 (cheaper than the online price!). And no, there is no such thing as a .org discount for Courtesy. They give the same 20% off list price to everyone.

 

Are the OEM NGK o2 sensors as big of a deal in terms of getting as NGK vs. Bosch spark plugs? Seems to be a significant difference in price (just like the spark plugs were)