Looking for mechanic in Chinatown, Houston TX.

When my 2012 Prius starts, its engine is very loud/rough. Greenbean battery installer showed me that my engine had found error codes by his diagnostic, such as P0300, P0301, and P0302. Last week, my friend helped me to change four sparks plus and Four fuel injections. Does anyone happen with such a situation before? What should I look to spend?