Just happened last night sounds Like Rattling noise coming from under my car very loud "1990 240sx" and also sounds like my engine has a ticking noise sounds kinda of like a lawnmower . I plan on selling my 240 :/ but before I do I need to fix this thing
Did A little Research
People say it can be a heat shield .. and I can tighten it . But the only thing is I dont know how or where the heat shield is even located or how it looks

and people say It can be a clog in my cat . I know where thats at just dont know If I can fix that my self and if so how


some people said lifters .. And Idk wtf that is Im clue less right about now
Thats pretty much it thanks

P.s I just got done replacing a head gasket valve that same day if that helps any