I just replaced my original 02 censor(went bad) with a GNX 02. I do feel it helped out the idle a little. Its nothing to write home about! But if you are replacing your 02 I would deffinetly suggest the GNX version. It is actually a little bigger. I also heard it reads quicker and more accuratly. It has a rounded tip where the stock one is flat at the tip. I purchased two of them from Kirban because if you buy two, it knocks five bucks off each of them. So if your buddy needs an 02 you could work out a deal. Thats what I did. My friend just hasen't payed me yet, ha haThe only complaint I have with the GNX 02 is that the wire is purple. I like the stock look, so it kinda bothers me. Some may say I am just weird. Well I couldn't agree with you more. My friend suggested covering it with electrical tape. I am weird, yes, but I won't ghetto up my car like that. So I'm gonna have to deal with it.