little background... 07 honda civic coupe ex 5-speed with 107k miles on the car. I bought the car blown up (original owner blew head gasket, but car still ran - i did not drive it). I found a 2011 motor with 27k miles so I had a shop install that motor. I was all excited to get it back because I got a smoking deal on the car and the motor... the idle is almost unbearable in this thing! there are not codes set for skip or misfire... I have replaced the plugs with new NGK plugs, new bank1 oxygen sensor... nothing helps. I read the 14 pages of people complaining about the issue on 8thcivic.com and did not see a cure. I dont know what to do, I can't stand sitting at idle in this thing. Once going down the road its smooth as can be and a very nice ride, aside from the bump/clang sound coming from front suspension at low speeds (yes I read about that issue too, doesnt bother me as much as the idle problem). My passenger side fluid motor mount looks great, no cracking or dry rotting... It just idles like it has a cam almost and sounds like that through the tail pipe. Its definately not a "dead skip" type of problem. Anyone figured this out yet?

 

checked codes today: P2176 Throttle Actuator Control System, P2135 Throttle/Pedal Position Sensor, P0404 EGR Control Unit... I guess the EGR could have something to do with it, but this motor has 27k miles!

 

have you taken it back to whoever installed the motor?