I own an 1997 Audi A4 2.8 V6
Had many coolant problems and blew a head gasket year ago. Got it fixed after much struggle. ($2700)
After getting fixed, I had a misfire cylinder 2; replaced coil pack, spark lines, spark plugs in summer 2007.
In December 2007, received a PO401 code: EGR Flow Insufficient. Cleared and carran normal.

Today, car sat for a day, started it, and idled rough, dropping RPM while in park. On highway driving, car "studdered" and loss power while driving, without regard to accelerating or braking, and "shook" while this happended, but did not shut off. Engine light came on, but WAS NOT blinking. With INTERMITTENT incidents while driving the highway, within 2 hours about 4 times ; I went to Autozone. CODED: Po300, P0302, PO304. (multiple misfire, Cyl 2 cyl 4) He said replace coil pack. Also experiencing some shity gas milage past few months.
Could it be the O2 sensor? coil pack, spark plugs,
What do you guys think is goin on here???!? is it okay to drive?

 

same problem with me but i only have a cylinder two misfire, code po302 i am replacing the ignition control unit waiting for the part to come in, maybe that should do the job, will update if it works.

suck to drive my car like if its a damn washing machine on spin cycle man i feel you

 

If your car is misfiring, it's not okay to drive it. The thing about coilpacks is that if one goes bad, the rest are going to go bad. Granted, all of your c-packs are gonna go bad, but you need to make sure you replace all of them at once. The way they function requires them to all be at the same level of performance; so if one is doing bad, and you just replace that, it could potentially put stress on your other c-packs. While you're at it, seafoam your intake with old spark plugs to clean out all of the shitty deposits, then swap in new plugs and coilpacks, and see if it makes a difference.


Edit: To understand why they need to be at the same level of performance, first we need to understand what they do. Coilpacks convert 12v electrical charge into very high charge (35,000+v) to jump across the gap of the spark plug and ignite the A/F mixture. If the voltage of each coilpack is different, then the ignitions are also different. Each cylinder needs to have similar/identical firing patterns, otherwise alternate stress may be placed upon it.

 

He is right!! Change all of them at once and do the spark plugs too!!

 

thanks guys, prob is... the coil pack is all one unit in my car. Cant replace each one/ (or 2) individually. I just replaced the whole unit last summer, you think it went bad that quick? Is it possible it just happened once and wont again?

Is there anythign else i should worry abouit? Should i clear codes and drive it until I code again?

 

could it possibly be fuel injector or O2 sensor? what woudl rule these out?