1995 Ford Explorer MAS and/or PFE cleaning/changing

Hello~
My question is regarding a problem with my vehicle. It's been running strangely and after a diagnostic I've been told that's it's the gas sensor? I'm assuming that they mean either the MAS or PFE sensors? I've also been told that this part needs to be changed and was never offered an option to clean it, do you know if cleaning these is the first step before changing them out? Because now this job is going to cost me abput $400 and after searing online I'm finding cleaning of this part is only about $33.00. And if I need to actually change these out. Is it something that can be done from a book, or is it tooo complicated?

Thank you~
Carrie