So I've run into another little issue with my 2001 BMW 325i and the problems are starting to get real. I am currently getting codes for lean mixture (P0171 P0174 P1083 P0185) it's starting to really affect driving. At a stoplight I can feel my car and see it dipping a small amount (about 1-100 rpms) but it will keep itself alive. now when I put my car into park allot of the time what will happen is my rpms will start bobbing up and down allot (about 100-300 rpms) and make it sound like my cars gonna stall out. I recently put in a new mass airflow sensor in from fcpeuro and it was the cheapest one they offered but it was still supposed to work. It was a bremi part so the real question I'm asking is are these codes a result of me adding that new mass airflow sensor or would it be a cold air intake/vaccume leak. I've recently repaired the boots on the intake and I've fixed allot of vaccume leaks. I'm thinking with the combination of maf and Cai that after this many years I should replace the fuel pump?