Hi all. I am new to Blazer Forum. I would appreciate anyone's input. About 450 miles ago, I had seafoamed my 1997 Chevy Blazer. I heard that sometimes the spark plugs must be replaced, but I am not sure if this is the case for me. I did an oil change after the seafoam. My Blazer felt amazing. I definitely felt the difference in the throttle, but recently, for about the past 120 miles, I feel like I am back where I was before the seafoam. I don't feel the power anymore. I drive an automatic. Can someone help?