I had my car scaned at autozone and they told me that i had i had a missfire in cylinder4, i am thinking that its sparkplug problem,
when i would boot on it sometimes it would shake for like a second and then it would boost fine, last night i was out with a couple of my friendsand they were all booting it and i was trying to keep up, but after i had downshifted to third, and then in 4 gear it wouldnt stop shaking and CEL come on, does anybody else know what it could be exept plugs?
should i buy them from the dealership or are autozone ones fine ?
is there anything special that i need to know?
thanks

 

Plugs

Coil Pack

Injector.

Most likely it is either the plug or coil pack. Run a search on how to diagnose coil pack problems (I'll give you a hint. If you switch coil packs from 4 to Cyl 3, where should the misfire be if the coil pack is the problem. Where would it be if the plug is the problem?

 

Yeah do what david9999 suggests. Troubleshoot the coilpack and see if it is the coilpack. But definitely change all your spark plugs. The autozone bosch platinum spark plugs are good enough

 

And what car is this? lol gotta include that.

 

2000 A4 1.8t, GIAC chip.

 

Id get some NGK BKR6E gapped at .028.
I wouldnt use plat in a forced ind. engine, especially when you are running higher boost like with a chip.
If it only misses when under load (heavy throtle)its probably a spark plug problem, possibly a cracked plug... If you have running issues/misses at all throtle positions then its probably a bad coil pack. swap the coil pack around and see if the miss follows like suggested^

 

I've been running the NKG platinums in my chipped 2000 for the last 85K miles without problems.

 

Ya plats will work... Copper will work better according to the facts:
Copperallows for a more complete combustion which not only provides more power, it also means less harmful emissions.Harmful emissions are not only damaging to the environment, they can reduce the life of catalytic converters and oxygen sensors.Copper plugsalso require lower ignition firing voltage, resulting in quicker starts and easier cold weather starts.A copper plugis ideally suited for race cars and high performance street cars. Today's performance engines are high compression/high stress applications. Many are supercharged andturbo charged. NGK's v-groove design with their copper plugsallows the ignition system to easily spark in these dense air/fuel mixtures. The v-groove forces the spark to the outer edge of the ground electrode whichhelps reduce misfires caused by high cylinder pressures that can cause the spark to beblown out. Got to be careful with forced induction engines because if for some reason you run lean, the affects are going to be worse than if you had a NA engine. Running lean with forced induction can cause the ground on the plug to actually melt and/or break off and eat a piston. A copper plug absorbs and disipates the high heat better and faster than any other type of plug. If for some reason a condition arrisesthat causes you to run lean, especially at WOT-high boost, having copper plugs is cheap insurance. Not trying to turn this into another sprak plug debate... Lots of people use plat plugs which is ok, im just trying to back up my "copper plug being superior theory" that i always insist on. Sorry..[&:]

 

I bought splitfire plugs today and put them in, and the guy at autozone told me not to gap them, i put them in but i still have the same problem, i havent checked the coil packs yet.
do you guys think these plugs are good enough?