Persistent P0106 Code

So, I have a P0106 code that will not go away, there are no other codes. I've got lousy fuel economy, a pretty low/rough idle and sputtering upon acceleration as well as lack of power. In the past five months I have replaced: all plugs, air filter, fuel filter, EGR solenoid valve and pressure sources switching solenoid valve(after checking for continuity and finding 0 resistance), MAP sensor, MAF sensor and all vacuum hoses. I was going to replace the plug wires but I checked their resistance and all were still fine. I have also inspected and cleaned throttle body and done several courses of techron injector cleaner. I did an in-line pre-cat exhaust back pressure reading, 0.5-1 psi at idle. Intake vacuum reading is 21-22 mmHg (which is within spec of absolute pressure of 70kPa at idle). No engine overheating, that I can tell according to in-dash gauge, though I'm waiting on a friends ir thermometer to check block temp as well as any unevenness that would indicate misfires. Needless to say, I am stumped with this problem.

year, model, miles, and trans please?

 

when did the code pop up? any work done at that time?

 

crossed vacuum lines, or a leak. did you spray carb cleaner around all of the vac lines / intake while the car was running? if it revs you have a leak. there should be a diagram on the under side of the hood, but you already know that.

 

the other thing i would check is a wiring problem / loose wire at a connector or corrosion.

 

it seems you have changed everything else, i'd do the wires as well. probably not the cause of your code but maybe part of the cause of how it is running.

 

check this out.

 

http://www.obd-codes.com/p0106

Edited February 28, 2011 by johnegg

Sorry, all that info and I forgot the car stuff. 1997 Legacy L, 2.2 L auto with 135,000 miles.

 

The code has been around since I got the car. I initially did a pretty thorough(carb cleaner then map gas) vacuum leak check before replacing all the hoses. And yes, as verified by chart as well as my service manual all vac lines are in correct positions. I also cleaned all grounding posts but forgot to mention in original post. I'm in the process of checking all the wiring but it all looks rather good. I'm doing visual as well as multimeter evaluations on all circuits using my manuals wiring diagram.

 

Also, changed the wires out just now with no effect.

 

Maybe brake booster? There's no loss of braking power and only a slight(1-2 mmHg) drop in vacuum when pumping the brake and it quickly returns to normal afterwards which I understand to be normal.

po106 is EGR.. i had this code on consistently when i swapped in my jdm 2.5 and didnt tap it for EGR... and it caused absolutely no problems..

 

so im thinking this isnt the cause of your bad fuel economy

I dunno about that... the link says MAP sensor, and that's what I've understood it to be too.

except..second gens dont have MAP, they are MAF

except..second gens dont have MAP, they are MAF

 

i think they may have both, but i'm not sure.

They have both, I replaced both of them. Maybe you're thinking of the 2.5 l you did, since mine's a 2.2. It mounts on the passenger side strut tower next to the air box and it has a vac line going to the pressure sources switching solenoid(mentioned above) which will actually switch between atmospheric and intake manifold pressure reading, in lieu of a baro sensor. It's got one open inside a bell housing for atmospheric and the other end is the vac line going to the intake manifold. Although the suggestion you raise about the EGR being related could be something, I know they can mess with pressure too. I only replaced the EGR solenoid valve (little red unit), not the EGR valve itself, since it seemed to behave normally when a I opened the throttle.

The EGR solenoid valve was defective, as was the PSS solenoid valve. Both had no resistance open circuits.

Just occurred to me you meant 2.5" headers, sorry. Maybe an exhaust leak then? The bigger header would cut back pressure just like a leak would and throw the code for me just like you experienced.

I have the same problems with my 1998 Subaru Legacy AWD . I checked the and replaced the fuel injectors and when I switched the electrical plugs to the injectors the car ran better then went back to a rough Idle traded them back same thing happened . So i looked at the scamatics on the injectors to me it looks like the ECM that is causing the problem and I will be buying a new one tomorrow and see what happens .......

Let me know what you find! And good luck.

Any resolution to this?

I found the source of my P0106 code today. I apparently had knocked the vacuum line that goes to the MAP (on the passenger's side inner fender). I noticed to short piece of hose that attaches to the engine was very hard, so I replaced it along with a couple of other vacuum lines. Code hasn't been back yet but we'll drive it around some more tomorrow and see.

Just replaced the NSS to clear P1507 code, then got another check engine light, this time P0106, a new problem. Based on this thread looked and found I had pulled off the vacuum line to the MAP while replacing the NSS. Thanks to all for this helpful advice.