Check engine light on***

[bandag1]

Hi All, I am new here, I did introduce myself in the proper column. Just wanted to ask a question and hear any suggestions or opinions.  Have a 2001 Outback wagon, 2.5,  automatic, 186,000k on her.  Has been running good. Recently have been having problems with the check engine light coming on time after time.  The code is PO507, idle higher than expected. here is what I have done or had a shop do.

 

replaced the idle air control valve

replaced the o2 sensor

replaced the throttle position sensor

replaced the gas cap

had the car checked for vacuum leaks, none found

cleaned the throttle body & checked the PVC valve

new air filter element

that's the main things,  my mechanic who has been very fair has pretty much given up.

 

the car idles at 700rpm in park when warm, but from time to time the idle spikes up to 1000 or slightly more and the CEL pops on. Does this when the A/C is on or the cooling fans are on but does it at other times too when both are off.  I am just about out of money to spend on this problem. My sister and mother drive this car but refuse to as long as the CEL is on. They are scared it will leave them stranded, (which I doubt).

Unless you folks can offer me something else to try I am ready to take the dash apart and pull the CEL bulb out, now I know that isn't the right thing to do but I am not doing it to try and trick anyone and I am not selling the car anytime soon, I would be doing it just to keep peace in the family and get my car back from them that they have been driving.  Now for my question, do any of you know if anything  bad will happen if I do this?   Someone said the car won't start, someone else said just break the bulb and put it back in as it is needed to complete the circuit. I appreciate any help you can give. Have a good weekend and I will check for replies.

 

[Fairtax4me]

When you replaced the TPS did you adjust it so you have .5v on the center pin at closed throttle?

 

There's a stop screw for the throttle lever. If anyone has ever messed with that it can cause idle problems.

[bandag1]

Yes the shop installed the TPS and did mention that it had to be set to a certain voltage.  I saw the screw you mention but have not touched it. When the car is not acting up it idles in park at 700rpm. (spec.)  and runs fine otherwise.

[DaveT]

Maybe a long shot, but I had random idle jumping in one of my older Subarus, it was caused by an intermittent coolant temperature sensor.

[bandag1]

UPDATE.

Well didn't have the nerve to take the CEL bulb out after talking to several people and got their scenario of what could happen if I did.  Sooooo, I bought a OEM used (from a car with 55k on it) idle air control valve, (threw out the aftermarket one I bought,)  put that on and realized the knock sensor had a crack in it from top to bottom on the upper side (hard to see) so I also bought a OEM new one, put that on, cleared the codes, and let her run for half an hour, idle stayed at 700-750 rpm after she warmed up, no more jumping around like it was doing. This weekend I will go for a  10 mile or so ride to see how it goes.  Really hope this ends the problems. Will post the results here next week, and probably drive it a few days into the week too.

[Caboobaroo]

I've seen issues with cheap Chinese idle air controllers. Had exactly the same issue a few weeks ago on a Forester. Customer put a cheap IAC on it, swapping it with a good used OEM one and voila, problem went away!