The Mégane II Owners' Club

Hi, thank you for accepting me in the group , I have a old megane mk2 2004,1.6 16v, and is working fine but only when is could outside has issues , is like failing to work at 750 rmp -800 rpm rpm and is working below, sometime the engine is stopping. and need to start again, only when is cold engine and cold outside when starting the engine , after few sec. all return to normal; when is hot outside no issue .

Not sure what to do, I changed spark plugs , new battery ,clean the throttle , apologise if this is not the correct post.

thank you.