I was accused of a capital offense crime by my estranged wife. I was found not guilty from a jury trial, during the trial my attorney caught her up in many lies and she admitted to giving untrue testimony in court. is there any way I can pursue a perjury case being she admitted to lying in court and if so what steps do I need to take
You can't pursue a criminal charge, only law enforcement can do that. Perjury is a crime, so you can report this to the police and they can, if they think it's worth pursuing, report it to your County's DA who can decide whether or not to prosecute. They may conclude that since your criminal defense lawyer was able to cross-examine your estranged wife and get the truth out, that nothing further needs to be done.
Note that perjury is relatively difficult to prove, and requires that the declarant knowingly giving false testimony, rather than simply being mistaken about the facts.
However, yYou may be able to pursue a civil claim for damages for malicious prosecution, to recover your legal fees, harm to your reputation, etc. See a tort litigator for help, they can advise you about reporting this to the police for criminal prosecution.
Disclaimer: I;m only licensed in CA. Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.