the + in the non sef url

What do you mean "+" sign in the non sef url? You mean "+" in the title?

index.php?option=com_ezautos&Itemid=99999999&task=results&cid=&trans=&tag=&pcode=&fuel=&doorsbody=S+U+V&colour=&year=&make=0&model=0&engine=&maxprice=&minprice=&direction=ASCPRICE&limit=50&limitstart=0
Do you notice the + sign in the url? This is the url that i can not change in sef url.
Actualy, i can change it. But when link pointing to the new sef url is clicked, i get 404 error.

You mean when you add alias?

Yes

I will check that and come back to you.

ok
tks