I have a 2004 xc90. I’ve recently had issues wit it not runnin right. Would stall out an then just wouldn’t even start. I’ve replaced fuel filter fuel pump plugs an coil pack. Still an issue. Unplugged mass air flow sensor an it runs good so I ordered a new one hooked it up today and back to square one of not running. What is the wiring piece considered as? seein I’m searching it with no results