...it finally threw a code about 2 weeks ago so I took it in for service. It was a faulty intake manifold gasket, and a few other things as well that were all taken care of under warranty. I'll have to check my invoice for the details, issue was our onboard computer compensates for these malfunctions on the fly and will not post a code until their is NO solution or something fails, so I drove all summer with intermitent problems. My VX is fine now, runs like new.