My Honda Accord 2000 EX 2 door coupe, 3.0L, has thrown a P0505 code after I cleaned the egr port on the intake manifold. After the car warms up, the idle will bounce between 1000 rpms and 1500 rpms, up and down, incessantly. How should I go about diagnosing the problem since the code only tells me it is a system problem, which could mean a lot of different things? Thanks.

SOURCE: 1998 HONDA ACCORD EX V-6

Sounds like your automatic idle control valve needs to be cleaned. Common irratic idle issue. Just remove, shoot carb cleaner onto ports until comes out clean. should be able to move valve inside easily.

SOURCE: Fule filter location for a 92 honda accord ex

http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528005f265

SOURCE: 2001 Accord coupe Codes P0505 - P0700 - 40-01. Any

those are manufactor specific codes and if u go to an offical honda site these year accords have serious known transmission problems that are still covered by the dealer even though out of warranty

SOURCE: 2000 ex v6 honda accord code p01399

it could be the coil or distrubutor cap

SOURCE: 2002 Honda Accord V6 check engine light on- local

po505 idle air control if this is the code all hondas do it eventully, small problem easy fix u have 2 choices either remove the idle air control motor and clean the inside of it u will find it's black and the spring inside is stuck clean it with carb cleaner or gum cutter any parts store will have this it's a dirty job it will work for awhile but to replace it is recommended its not expensive for a new one which u can get at any autoparts store autozone,advanced,napa etc. there is only 2 bolts in most cases maybe 3 i doubt it though if u go online t google and type in th eyear make and model and engine size in ur case it's a 3.0 v6 and look for idle air control locations u'll find it to do this job a shop will charge u anywhere from 100.00 for diag to retrive the code plus the part and the labor so about 250.00-375.00 it will only take u honestly maybe 15 minutes to perform only tools needed are a 10 millimeter wrench there is only 1 connector to disconnect and ur done if u do this u will still have the check engine light because u have not cleared it from the computer to do this just disconnect the negative battery terminal (the black one or has a neg sign - don't disconnect the positive side +)for 5 minutes then reconnect and the computer will have reset no more light. good luck it really is that easy