We are not aware of any specific reliability issues with converting a CX-7 to LPG. However, as we understand it a number of converters aren't willing to do one on a CX-7 because it is a direct injection turbocharged four-cylinder engine. Traditionally these don't respond as well to LPG conversions as much as a low-stress large capacity engine. Sadly the biggest problem you will face these days is finding an LPG filling station, as numbers are reducing every month.