markkram

have a honda with 200k miles on it and never had a problem till the cat when bad. i noticed that the intake manifold looked blown so i replaced it, replaced the hydrolic chain tentioner and of course the CAT. bled the coolant re learned the idle tried spraying for vacuum leaks, plugged up all vacuum lines, and still have a high idle. it'll through a code for a IAC p1505? i think. i replaced the IAC when i ran out of ideas and cleaned throttle body backed off the TB cable and nothing. if i put a thumb on the IAC it'll smooth out the idle but if i block off the TB it'll kill the engine and hold vacuum on my hand. TPS volatage is .5 new TB and plenum gaskets. high way driving is fine city driving is fine minus putting an effort on the brake pedal just to keep it stopped. i'tll idle at 1100 in drive but once i put it into nuetraul or park it rises to 5k. its driving me crazy any tips or directions?

VegasInvasion

how does one "blow" an intake manifold...
You have a huge vacuum leak. I'm moving this to the proper category.