Drive like it missing i tune it up pull it up to a tester it said misfire cyclinder 8 plug are aready set new wire ac delco the tester code was 308 and also said running lean. where is the cyclinder 8

ignition wires is agood start , check all wires for spark out put with spark tester saves a lot of time.

Cylinder 2 Misfire Detected po302 . Evaporative Emission Control System po440 The last digit on a misfire code indicates the cylinder number. A code P0302, for example, would tell you cylinder #2 is misfiring. Chances are the misfire is due to a weak ignition coil. Did you change the pcv valve? Remember to put the o-ring on the new one or this problem will happen.

DID YOU GAP SPARK PLUGS AT 0.060 FOR 3.1L ENGINE OR 0.045 FOR THE 3.4L ENGINE.DID YOU BUY AC R44LTSM SPARK PLUGS. DID YOU BUY AC DELCO SPARK PLUG WIRES.BECAUSE IF YOU BUY WRONG TYPE SPARK PLUGS AND WIRES CAR WILL MISFIRE.

Need to take off the plastic on the top of the engine (the plastic box) and the air cleaner hose that goes over to the throttle body. There you will see 6 coil packs. Remove one at a time (2 bolts each), under the coil pack are the spark plugs. I recommend using AC Delco 41-103's for the plugs, will idle better with these. When pushing the coils back on, make sure you hear or feel a little click, too many people install these back on incorrectly, which causes more misfires. If the misfire isn't corrected with the new plugs, check the coils. I also recommend cleaning your throttle body while you're at it, make sure to disconnect the battery while doing this. After it's clean, drive around for 5 miles or so to reset the computer.

If it has a very bad misfire, your check engine light should be on and OR blinking. If it's blinking, don't drive it. You'll probably pull a code of p0300, p0301 & so on which will tell you which cyclinder to focus in on.

The codes mean as follows
PO300 multiple cylinder misfires
PO301 #1 cylinder misfire
PO308 #8 cylinder misfire
Some of the more common causes for these codes popping at once are, if you went through a big
puddle and the engine and wires are wet or the distributor cap and/or wires are bad or the camshaft
sensor(located inside dist cap) is bad and sending false signals. Hope this helps.

p0308 is cylinder 8 missfire, it could be the plug on that cylinder,wire, or coil. also make sure the injector for that cylinder is ok!! have a good day!

The plugs shouldnt matter they are the same just different manufacturer.

Have you distributor module checked out.

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it means you have a misfire on the number 6 cylinder

this could be caused by a whole lot of reasons.

start by inspecting for a bad plug wire if it has them

check for fire on the cylinder with a spark test tool from local part store

if it is a coil-on-plug set-up, check the coil for fire

replace coil/plug wire as needed, replace boot on coil if coil needed, replace spark plugs

try a new crankshaft sensor not hard to change 2 bolts and a wire

I would recommend going back with ac/delco platinum plugs.Some of these "high performance" plugs dont work well in newer gm vehicles.The computer is sensing more than one cylinder misfiring and cant determine the cylinders the style of plug your using could very well be causing this