I did drain old gas. But new gas with sea foam. But hasn’t helped. Maybe even a little worse. I have a scanner. Has some live data. Unfortunately I thought it had misfire monitors but can’t get that to work. It does show fuel trims. Ignition retard. But I don’t know what the correct values should be...

Yea. Was curious because some say using synthetic in a van that previously had conventional oil will cause oil leaks. I have the manual. Searched high and low for oil specs. I will download another. Thanks for your help

Hello everyone! I just bought a used express and could really use some advice. I have an engine code for random misfire. The van has been sitting for a year. Ran well when parked. Can anyone give me some tips on diagnosing the problem. I do have a scanner but it’s pretty low end.It’s a 2003 express ...

Hello everyone! I just bought a used express and could really use some advice. I know it has 5/30 viscosity oil. But do I use conventional or synthetic? What did it have when sold new? It’s a 2003 express 3500 with vortex 6.0. Any help would be greatly appreciated