Thanks. Just getting back to my posts. Will give it a try.

Air filter is good and fuel economy is about what I would expect... around 25mpg. I am not sure about the plugs, but no messages being displayed.

Every now and then... and occurring more often... my C70 with 89,000 miles will start, rev to 3 or 4 thousand RPM and then just shut off when I let off the gas. Then it takes a number of tries to restart with a lot of just turning over. We live in the Washington, DC area and this occurs in both cold...

Thanks. My 2004 C70 with 89,000 miles started the same slipping in the last few weeks. I will be sure to get the fluid changed... properly.