Hey everyone,

I just change my plugs and wires today and I just got codes p300 and p308
I used STi 8mm and Bosch plat 4s.

Any ideas on where to start?

 

Unplug, adjust, re-seat. View under hood in total darkness to look for arcs. Bad thing about misfires on "end of the block" cylinders is potential for head gaskets, hope no coolant loss, white smoke, etc.

 

No coolant loss or white smoke. I did have a wet plug on #8 when I pulled the old one. What is that from?

 

If the codes happened after the plug change and #8 is wet, I'd suspect a bad plug. Swap the plug with the one next to it and see if the misfire code changes. If it does, the plug is bad, if it's not, then either the plug wire on #8 (or the injector, or something else is going on). Personally I'd suspect the plug, yes I realize they're new but think about it this way, why do new parts have warranties?

 

If not fuel or oil, which would burn off with good spark, but you don't have spark. Certainly swap a plug or wire. If you have good spark, then coolant. Rear area of head gasket is slim by the outer cylinders, in particular the rear. Might be time to consider a mechanic in a jar product, like http://www.irontite.com/store/index....&products_id=2 . These products can work in a range of cases, but might not be a forever fix, and could cause problems if cooling system is partially clogged. I would think that if they are going to work, a small leak might be easier to have success with than a big leak.

So the rest of the partz vulturez can stop ruffling their feathers on the upper branches of the shade tree, it is important to note that it is not as good as a new head gasket, there are other tests you can run (like dye in coolant, which would show up as flecks of green on the plugs), and you may end up doing the head gasket and cleaning out the radiator.