p0303

Hi there! P0303 (misfire cylinder 3) just popped up after 121,000 miles on my 2007 CX-7 (i.e. turbo). Very unfortunate since it was running so nice lately. Anything different lately? Well, new gas tank 30 miles prior (doubt that is the problem), and 2 tanks ago I put a can of gumout in the gas...

Hi all, Stock P5, no mods. More misfire problems, but why so freakin' soon? August 2015, at 301,375 Miles, CEL came on, two codes: P0302 & P0172 Did all of the following: - Ignition Coil Packs (2) - Wires (2) - V-Power Spark Plugs (4) - PCV + Grommet (was a wreck) - Professional...

Hello all I really need some help. Two weeks ago out of the blue my girlfriends Mazda Protoge5 started running like crap. I took it up to the parts store and read the code which was a P0303 a cylinder 3 misfire. Same thing happened to her last year so she had it in the shop and had new plugs...