had a master cylinder rear seal leak for awhile, about 100mls every few months, once i verified it wasnt leaking anywhere else i came to the conclusion it was the master cylinder. brakes worked fine but had to keep an eye on brake fluid level. pia to get so i procrastinated on removing the master cylinder as the fuse box was in the way and had to be removed before i could tackle it. next issue that developed was a check engine code mil of p0171 retrieved using a scantool, a lean condition code as fuel trims maxed out on idle and somewhat got better under throttle. i did the water and propane air intake vacuum leak test and found, after some considerable time, that my brake booster had cracked which was causing the vacuum leak/air intake leak hence the p0171 and progressively worse rough running car. so time to finally tackle the job. 1st video is the fuse box removal, 2nd video is the steps in removing the brake booster/master cylinder . .