KDELUCA

I am new here and will finish the profile but wanted to get this posted asap. I am breaking down and asking for help. I have been trying to fix an issue with my wife's 2006 Honda Civic LX for about 4 months. I have tried allot of different things and nothing seems to fix the issue.
A P0507 code is active. Can be reset but returns after awhile. Throttle body was recently changed by a mechanic. No relearn procedure was done. I followed the manufacturer procedure dozens of times. Making sure no additional loads we're active and allowing fan to activate before letting off gas to start the idle timer.
Went through ac Delco plugs...recently switched those for NGK laser iridium's. And cleaned battery and engines grounds and added dielectric grease to the boots and plug connectors the same day. After doing the relearn that time I achieved a 750 rpm idle and it seemed to drive much better but after a few starts the code returned and the high idle as well. About 1050-1250 average. I have CAREFULLY cleaned MAF and replaced air filter and cleaned all sensors around throttle. New oil change as well. I can see the upper intake gasket needs replaced and I am leaning toward that possibly being the culprit. I have not yet pulled and inspected the pcv. I carefully cleaned the egr today with carb cleaner.
Any time an electrical load is activated e.g. radiator fan or windows or even bumping the steering wheel...the rpms jump up about 200-300 and slowly drops back down to about 1100. Also...when you tap or press the accelerator and let go...it drops quick but then bounces back up quite a bit then slowly drops room again. Also it is causing an issue where the engine seems to wanna pull the car hard as soon as you let off the brake. That makes braking or coming to a stop a difficult task when driving. She is a bus driver and can manage to deal with it but I am not happy with letting my family ride in what I believe is an unsafe car right now. I read somewhere that a releatn procedure may be needed by the dealership with a scan tool. And that the manual one just doesn't cut it for this model maybe? But then I am also leaning toward an electrical issue because of the rpm jump with load. But then I am confused because of the rpm jump after gas release. If ANY help can be offer it is much appreciated. And thanks for the time.

Colin42

Is the intake tube between the filter housing and the throttle body compromised at all?
definitely look at getting that intake gasket done.
can try spraying brake clean around the intake system with the car running to see if you notice a change in the idle

ezone

When did this code start showing up? Was some work done immediately prior to this code appearing?


How?

Absolutely true. There's specific info about this if the dealer tech searches for the P0507 code.
Start here. Assuming nothing else is really wrong, I would not waste any more money on anything else.

KDELUCA

Thank you Collin and ezone for the replies. To Collin, the housing itself has been cleaned and looked in good condition but I will make sure to double check for any damage in the morning. Possibly the hose from the housing to the body is cracked somewhere.
to ezone, the P0507 code appeared shortly after the throttle replacement. But at first the car was shifting VERY hard. I could literally see the whole engine almost about to jump out of the hood when shifting from park to drive. My friend was freaked out. I never seen anything like it. So I changed the spark plugs and did the manual relearn and it went away. Eventually the MIL lamp returned and with the same code but no longer jerking at all on shifting.
Also, I can see a lot of what looks like wet grime and grit around the gasket. I assume there may be several pinhole leaks pulling in air that I cannot feel with my hands. I can get the gasket for about $40 but I wanted to ask for help before I continued dumping money into this. Is it possible it's an electrical issue? Which may be much harder to diagnose than a vacuum leak I assume. I was told by the dealership that this model is equipped with something that allows the alternator to adjust voltage when a load is requested in order to compensate for the rpm drop.
Since the throttle body is electric, I have been wondering today if that is why the rpms bounce up when letting off the gas. Maybe the alternator is seeing letting off the gas as an activated load being sent to a sensor? Sorry if I'm not tech savvy. I'm no mechanic just trying my best here.

ezone

ALL STOP. Take it to the dealership and have the learn procedure done.

If necessary tell them what I said in my previous post about searching the code # in their service information, it outlines exactly what needs to be done.

Alex2830

How much the dealer will charge me for the idle relearn?

Colin42

Probably an hour of labour, call and ask