Hi, I just had my spark plugs along with my thermostat replaced. About 15 mins later my check engine light came on letting me know it was a misfire. I have a 2005 Pontiac G6 v6 and the service codes are p0300 and p1626. I really want to know what the cause could be.

SOURCE: transmission fluid on a 2005

Please see the solution I posted on the other page where you asked about the transmission fluid.

http://www.fixya.com/cars/t9005135-2005_pontiac

SOURCE: Code P0300 on a 2002 Pontiac GP with misfires on #

try switching one of the other coil packs with one of the bad ones. if this works then there you go. another way of telling if it is a coil pack is to disconnect the spark plug of the affected coil pack. if its a strong coil then you will hear the spark as well as see it. compare it to another plug boot that has the good spark. it sounds to me that it is a coil pack. i just changed one about 2 months ago with the same problem as yours.

SOURCE: pontiac g6 2006 2.4l codep0300,idles is good but

that code is an engine misfire. try changing the plugs and wires. if that doesnt work you may have to change the coil packs.

SOURCE: 2006 pontiac g6 second cylinder misfired

the p0302 code gives u a place to start u can have perfect maintainance with ur car but parts wear out ,go bad,or get damaged-- misfire in cylinder 2 can b a spark plug,a bad wire ,injector starting to clog -start with checking the plug and wire

Testimonial: "thank you will do"

SOURCE: check engine light came on along with check gas cap

Did u have engine codes scanned? If not, have it done, as it may indicate the problem. Let me know. (most parts stores will scan for codes free) .