Hi i have a 02 astra 1.6 8v z16se.
tonight i put in £20 petrol at BP and then started driving down the motorway to work. a few miles down the motorway the exhaust emmission light came on. i stopped and everything looked and sounded ok so carried on to work and it ran fine. did a peddal test and got 0304 cylinder 4 missfire but it dont sound like its misfireing.
any ideas welcome sorry it a long post.