I was lookin at the NGK website at spark plugs.. and i saw oxygen sensors. i have seen these other places too.. worth anything? good buy?

 

Why would you want to buy o2 sensors just to buy them.Our engine has 2 upstream and 2 downstream o2 sensors and the ony reason to replace them is if they fail or become lazy.The o2 sensors switch back and forth hundreds of times per minute telling the computer to either richen the fuel or to lean it out.

When an o2 sensor goes bad the computer dosent know what to do so it just dumps a preset amount of fuel into the engine to keep it running.When a o2 sensor gets lazy it switches very slow and can cause all kinds of drivability problema as well.

 

If they need to be replaced I place my vote for bosch. NGK make good plugs, I don't know about the o2's. But like superchargedg said, they only need be replaced when they don't 100% work anymore.

 

Actually O2 sensors get sluggish with age and the slower they switch the less likely the ecu is to hone in on the exact A/F ratio to optimize emission and fuel usage.

Most last 80-100k before needing replacement.

 

I have over 106,000 miles on my 03 Coupe, and I'm getting ready to do a major maintenance job. I'd also like to replace my O2 sensors, since I've noticed my gas mileage has slipped a little recently. I like the Bosch sensors, but I'm curious - is there a benefit to using the "After Catalyst Right/left side and before catalyst" set versus the "before/after catalyst universal" set? The former set costs over $120/sensor (total cost of $480!), the later set only costs $200 total (on ebay - $50/sensor). Is there a reason for the cost increase?

 

@ Q45Tech, please correct me if I am wrong, but for the sole purpose on fuel efficiency and emssion, only the front set of sensors that are responsible for that. The rear set (Aft of primary cat) is for cat efficiency monitoring.

In terms of replacement interval, I do believe that 80-100k is a good mark.

 

The universal ones will not have a plug on the end and you will have to cut the connector off your old sensor and solder it onto the new one. That's what the extra ca$h is for - the convenience of not having to solder and the confidence of having a good connection for all the wires.