when I Drive my 2002 envoy the transmission do not kick in until about 3 or 4 miles and then a kick in very slowly in then it drive what's the problem
Not sure what you mean by kick in. If your going 3-4 miles the transmission is working. If it's slipping then check your transmission fluid level while it's running. It should be red like cherry Kool-aid. If it's low add the correct fluid to the correct level. Then look for a leak. If it's full but brown and smells burnt then have it flushed. I highly recommend BG brand.