I check to see if my sparkplugs were lose cause my f150 ford 2002 truck was running bad and now it got worst?

I check to see if my sparkplugs were lose cause my f150 ford 2002 truck was running bad and now it got worst?

And what do you want? Someone to tell you how to fix it? Sorry, no can do. Read the codes.

Okay, were the spark plugs loose? What exactly is the engine doing? Details! I'm sure the check engine light has come on already. Take it to auto zone and have them scan it for free.

No sparkplugs were lose just want to know what my be the problem

So many things could cause a vehicle to "run bad". Symptoms? CEL on? Which engine? Which transmission?