My 1996 Toyota Paseo is having a problem with its spark plugs, it is eating them. I was having some issues with misfiring so I gave the car a tune up and after about a month started having misfires again. So I pulled out the plugs and the on in the fourth cylinder is missing the post and is all black. This is the second time this has happend. I'm not sure why this is happening? A friend thought that I had a bad fuel injector? Does anyone know what's going on? Thanks.