Took a few minutes out of my day today to run some Seafoam through my 02 GT. I ran about 8 ounces er so through the vacuum line. Here is the aftermath....
That is carbon that spit back out the line through the funnel as I shut the car off.
Here's a video of the smoke coming out the exhaust. Not really very much at all. I was kind of disappointed there wasn't more. And after all was said and done, I don't notice any kind of performance difference at all.
After Seafoam video by skeelo58 - Photobucket