Toyota Repair: Error P0171, P0174 - will realignment of the steering and suspension resolve the problem

Question
Last week, the check engine lights, traction Control, master warning lights and Check VSC System of my 2008 Toyota Camry XLE V6 came on. There is also a "hissing" sound  from under the steering column when I applied the brakes

I brought the car to auto parts outlet to read the error codes, it came back with a P0171 and P0174. But when I bought it to the mechanic, he did a realignment of the steering and suspension. The lights did went out, but the "hissing" sounds remains. It seems that both codes are not related to the steering and suspension system.

I'm wondering if the root cause was really resolve.

Thank you

Answer
Those codes are for a lean/rich fuel mixture and have nothing to do with suspension or alignment, it sounds like there is an intake air leak going by what you are saying about the hissing noise, since this noise happens when the brakes are applied there is a good chance that it has a defective brake booster unit so it should be checked for that by a competent mechanic. The reasons the lights went off is that they cleared the codes in memory, they will return after a while because the real problem wasn't fixed.