engine misfiring? on 2005 Honda Civic

Hi I have a 05 honda civic LX 5 speed with 74000 miles. Has a little bit of a rough idle, the check engine light is on and blinks when sitting in idle. When driving it stops blinking and just stays on with out the blink. OK, so got a dianostic and it says it is misfiring in all 4 cylinders. We changed spark plugs, didn't help. Then we noticed that when we unplugged the first coil pack closest to passenger side while the car is running it didn't disturb the the idle or the way the car was running. So we switched the coil packs around to see if the passenger side would start working or to see if coil pack went bad, still made no improvement. So we thought it was an injector, replace that and still same mild rough idle with check engine light. By the way the acceleration seems fine with no hesitation and same goes for starting the car, both are fine. Just in idle for the most part is the problem. Ok so what do you think I should do next or what do you think the problem is? Thanks!

by in Carol Stream, IL on September 29, 2009
2 answers 3 comments
ANSWER by , September 29, 2009
Can you post all the trouble codes that you are getting? Be careful to not include any codes that were created by unplugging coil or injector while it was running. Also, check for vacuum leaks in the intake system, especially the intake manifold, and check cylinder compression in all cylinders.
COMMENT by , October 05, 2009
Here is some info regarding the diagnostic codes you received: http://repairpal.com/OBD-Code-P0300 http://repairpal.com/OBD-Code-P0301 http://repairpal.com/OBD-Code-P0302 http://repairpal.com/OBD-Code-P0303 http://repairpal.com/OBD-Code-P0304
ANSWER by , September 29, 2009
Give me a list of the trouble codes al give you a probable cause for each.
COMMENT by , September 29, 2009
I don't remember the specific codes autozone told me, so I'll take a trip over there and tell you by friday. Thank you all for your help!
COMMENT by , October 04, 2009
The Codes are P0300,P0301,P0302,P0303,P0304 Now we are thinking the problem is that the Idle Air Temperature (IAT)sensor went bad. What do you think? Thanks again!