i recently bought a ford ranger and i decided to check the radiator because when i drive it for a little to long my check engine light comes on and when i did it smelled like really bad catfich and the water was brown plus the cap had a mud-like consistency on it any tips im thinking about washing it out fyi

 

1993 2.3l Ranger
Should always include that with questions
Manual or automatic?

Clogged radiator or overheating won't cause CEL(check engine light) to come on, so something else is wrong as well

Yes, you can try flushing out the cooling system, but from the sound of it a new radiator would be a good idea if current coolant is "sludgy"
Just fill with water and run it a few days then if No Leaks, drain and fill with coolant