I have 150k on my 95 Maxima and have never changed the O2 sensors. I'm not getting any codes thrown at me. Is is worth spending the money to change them out? Those of you who have changed your O2 sensors, did you feel any increase/return in performance on gas mileage? Let me know. Thanks!

 

check if you have any codes. the light might not turn on as they might have some life in them. if they are going, just replace them. they will increase performace.

 

I had 140k on mine when I changed them out, thinking something might change. But nothing changed. I ran a Diagnostic Test Mode II on my stock and new o2 sensors and really nothing much changed.

Do you know how to reset your ecu? If you do, then you know the proceedure to get into Diagnostic Test Mode II. If you need more help, download the 1999 FSM from my website and read the EC chapter, somewhere page 51 or so. What you're looking for is at least 5 adjustments (lean to rich and back) within 10 seconds.

PM me if you need more assistance. In a pinch, I'll snap a pic of the FSM and post, but easier if u just dl the FSM.

Jae

 

well, they won't improve WOT performance...but they will increase mileage and non WOT performance....the shop that did mine however must have done something else to my car....they replaced with them with the OEM bosch ones....my car has never felt the same since....not as fast as with the old ones...!!

 

although that had to be something else the shop did to my ride!

 

if your 02 sensors arent bad u wont see a difference. I've had codes and had bad 02 sensors and yes i felt a differeince in all areas of the powerband. But i wouldnt waste my money replacin them unless u got the code. I dont know for sure but something happens to these sensors that kills them, not age but probably the type of flow of gas they might get or something? so yours may have jsut been taken care of...

 

I agree....you won't see a difference...if they aren't bad...mine were the originals that came with the car at 125K miles or so....I just did it hoping for better gas mileage...but I didn't even notice that!! lol...so I guess mine were actually in relatively good shape...