Oil pressure sensor and possible lifter issue
 

I Just changed my oil and since I bought it over two years ago it does like to put out white exhaust when first starting. Last weekend it was acting funny and wanting oil but it isn't leaking anywhere, this weekend it was acting worse and making alot of noise, even put oil in but I'm thinking it's the hydraulic lifters and hoping it won't be a while engine change. For that price I could get an over priced nicer looking one. If it is the lifters how bad is that to do and will it only be that one part to change?