how many miles do you have on the car? theyre supposed to be good for ~80k miles if not in a dirty environment.
here is what i did as a cheap replacement
http://www.ineedawebsite.com/Blazing...lth%20CAI.html (make sure its compatible with a PZEV)
and short trips will definitely keep your mileage low, seems like i need at least 5 miles to get my car up to temp.