01 SC2 codes, 0302,0405, 1301

[theunpaidBill]

Morning!

So I have an 01 SC2, DOHC, manual transmission that I use as my commuter car. It does roughly 400 miles per week. It's got 277K miles on it, and runs better now than when I got it 4 years ago. Uses about a quart of oil every 4000 miles (I run full synthetic and change it at 6K).

All in all it's a great car.

It's started idling a little rough when it's hot. I changed plugs and plug wires, but the codes came back, so I'm asking for a second opinion on step 2.

Codes are:
P0302 - Misfire cylinder 2
P0405 EGR flow sensor A circuit low input
U1301 Class 2 short to battery

I thought the 0302 would be cured with plugs and wires, as it definitely needed them. My next plan for it is replacing the coil pack. Should I just do the one or hit them both while I'm doing it?

The research around here I see says the 0405 is not unusual for an aftermarket EGR valve because they are not that great. Is my best option to buy one with a warranty and just replace it whenever it starts doing this? Autozone has been solid with warranty replacements.

I don't know about that 3rd one, could it be caused by the EGR issue? I replaced the battery a few months ago and haven't had any problems with it since.