Question about 1992 Corvette?

[brad b]

My friends Corvette has a very rough idle. It never levels out! Sometimes when you put it in gear it dies. It is a 1992 with an LS1 auto trans. Only has 90,000 miles. DOES NOT THROW A CODE. I was thinking it has to do with the secondary ignition system. I just want a second opinion...

 

[Peter]

.check egr valve for sticking open but also they are known for intake gasket leaks -replace gaskets hope this helps