its a vacume egr. There are never any check engine lights or codes on computer. It only idles good untill the engine gets hot. When the engine is hot it doesnt matter if its in park or drive or neutral all 3 ways it will be very eratic and want to die. Ill try to pull on egr when its dying. the problem is i have to drive it for 10-15 mins till it runs badly and im usually by myself.