Jb4ker96

Hey there people. I'm making this thread because recently in the past week when my car is cold it making a lot of noises.
So when you start it it's perfectly fine kicks over easy as! But soon as it starts you hear a great deal of popping noises around the exhaust area and you can feel the vibrations under your seat. Then about 30 seconds later you start to smell this really really bad odour! Worse the usual smell you get Then about 45 seconds it drops from 1 and a half thousand revs to 600 then bounces back to normal then everything is fine after about 1 min then warms up fine after that. The car is a 2004 model had 124000 ks new spark plugs and leads have cleaned the intake system and throttle body and has had fuel injector service done about 10000ks ago. Oil change has always been done every 5000ks and I have only had the car for about 7 months Any help would be appreciated thanks