My car had the SES on and after changing the Air filter (which has always cleared the problem in the past) the SES did not clear, seeing how it had 93,000 miles on it. I changed out my spark plugs (bosh double platinum) I purchased at AutoZone and the Cables purchased at O'Reillys. I started the car and the service engine light was still on, but my vehicle was running horrible now(missing constantly, loping) I decided to go around the block with it. It was sluggish and the service engine light would start flashing whenever I accelerated. I went to AutoZone and they put a OBD II reader on it and the codes returned were P0300-multiple misfires, P1404-EGR Closed position performance. I used a gap tester to ensure that my spark plugs were gapped at .060 mm. I used a spark plug wire tester to ensure all plugs were firing. I ohmed out the spark plug wires and they were within specifications. I tripled verified spark plug wires were correctly installed. I tested my EGR and the coil ohms was in range. The 5V to the EGR was there. I was wondering if there is any other possibility as it appears I have a bad EGR valve. Has anyone else experianced this fault combination or have any other Ideas on troubleshooting this problem or an explanation of what P1404 code means is the EGR closed and won't open or is it being commanded closed but isnt?
