Possible O2 sensor??

[Kyle97-clipse]

Okay so I recently noticed that when it is raining out or very damp that when the motor is cold and has a load on it like in 4th gear it will just stuttur for a few seconds. It only does this once and then its fine, and only on rainy days. Ive had a CEL code 21 I think i forget if thats upstream or downstream though. Anyways would that sensor maybe be causing this, thanks

 

[devildog0905]

It doesn't sound like an O2 sensor problem... are there any other symptoms? When there is a hesitation, it is usually a fuel or air problem.

 

[Kyle97-clipse]

Nope no other symptoms my narrow band A/F gauge goes rich though I managed to take a look at that. It only does it for like 3 seconds and only one time its a really strange problem. Only when its rainy or damp too thats what is confusing