My SES light came on a few months ago. I went to Autozone and they said it was my 02 sensor.

I wasn't too worried about it until it started to idle like poo. I went back yesterday to find out which sensor it was so I could order one. The girl told me it was a cylinder 2 misfire and that I just needed a tune up.

I bought new Bosch plats (man those rears are a PITA) and put them in last night. I also replaced my PCV valve.

The car seemed to idle much better. Before it was real rough, and sometimes when I would come to a stop it would dip below its normal idle, the car would shake for a second, and then it would go back up. However throughout the day it did seem to give me some intermittant idle issues.

The light came back on today. I went to see a buddy of mine who is a Ford mechanic because I needed a tire rotation/balance anyway. He ran it and it came back with I believe 1320 (02 sensor) and 0302 (cylinder 2 misfire).

He said I have a bad coil pack and I'll need to replace it. He said the 02 sensor isn't worth replacing - in fact he gave me something to bypass it with.

Anybody had a similar experience? Should I go ahead and replace the coil pack? Best place/price to buy?

I do have a Random Tech cat - did this cause it?

 

P1320 is an ignition code, not the o2 sensor. both codes point to your ignition. you can choose to replace the bad one or go ahead and bite the bullet and replace all 6. i always advise to do all 6 if you can so you dont end up replacing more in a short time. you can get a quote for the coils from jerryromenissan.com online and use MAXIMA and it should knock off 12%. if your friend thinks its the o2, then that code may match up to ford diagnostics but some codes are manufacturer specific.
also watch out for misfires from those german plugs you put in. alot of 4th gen guys and some 5th complain of very poor performance and even misfiring from bosch. if thats the case, then replace with ngk copper or ngk plats (oem) in the stock heat range.