help

[chaorewjay]

hey guys, i am new to this site but i just bought a 2000 jetta 1.8t that i need some answers for. When i bought it the check engine light was on for the upstream 02 sensor, i changed both of them and it ran fine for a while. Now all of a sudden this weekend my check engine light started blinking and when i scan it cylinder 1 misfire comes up. Also all of a sudden the car has a very lumpy idle and it has a signifigant lack of power also it takes forever to rev up going through the gears. So far i have replace the plugs with denso irridium plugs, changed the fuel pressure regulator and hose for it, i changed the fuel filter also. I have no idea what the heck the problem could be, any help to guide me in the right direction would be greatly appreciated. If it helps the car has a turbo back exhaust, an apr cold air intake and was tuned by ap tuning. I'm not really sure the guy i bought it from knew what he was doing when he put in the intake because it doesn't look right to me but i want to fix the first problem then go through the rest of the car.

[deletedo1m]

How do the plug wires look? Was it raining/wet out?

[chaorewjay]

It has coil packs, no wires for it. And no it was dry, it does it all the time.

[Rockerchick]

Did you replace the coil packs?

[chaorewjay]

I Tried. I started with the cylider that was misfiring and put a brand new coil pack in and after that cylinder was completly dead so i put the old coil back in. I'm going to try to put in 4 new ones and see what it does but i believe its another issue.

[Rockerchick]

You can also swap them around and see if the misfire moves. If it does, that coil pack is bad.