So im only getting 1 code p0300 its misfiring and running kind of rough at idle. Im in the process of doing new intake gaskets plugs coils and valve cover gaskets but am going to do a compression check. Also have a feeling clogged precats is my problem but any input is appreciated to help with this code thanks

 

Is it always misfiring or only sometimes?

 

Try disconnecting each coil and feel any changes in idle speed. if you disconnect an ignition cook and don't feel an idle speed change, that ignition coil, or spark plug may be bad.

 

Hey thanks for the replys it seems like its misfiring most of the time but it feels like it stops while driving sometimes. I currently have it apart eith intake manifold off have 6 new plugs coils and intake gaskets going on once i get some decent weather also doing a compression check before it all goes back together will keep you all updated thanks again for the replys all help is appreciated

 

If it's not the coils then you'll have to look at injectors most likely

 

BINGO X 2

First way to diagnosis then work up to spark plugs.

Last repairs I did lead to one bad coli.

 

Thanks guy it was the coils it just hard to unplug some of those coils in the back behind the intake. Replaced all spark plugs and coils and no more misfire