can you provide a link to where you read that fixing a code violation is deductible. it could be old case law that has been superseded by the IRS regulations 1.263.
here's an link to an explanation
https://www.dbbllc.com/newsletters/focus/mar2012/irs-clarifies-capital-improvement-vs-repair-expense
note that short of a Supreme Court decision, the IRS is not bound by other court decisions. and in some cases even the tax courts don't agree. an example is what is reasonable compensation which differs from court to court. then there are cases the IRS constantly loses but continues to litigate every time.
there is no absolute way to prevent an audit. your return might be one of those chosen by the IRS at random
even the IRS auditor could matter. some are more willing to listen to taxpayer arguments then others.
even the time the agent has been on the job can matter.
