Synthbent715

Hey guys, noticed my 05 auto xA idling a bit rough about a month ago. A few times, it even felt as if it were about to stall at a red light. I cleaned the TB and added some fuel injector cleaner to the tank and the idle seemed to get a little better, but still is a bit rough, especially with the AC on (about 400-500 rpm's at its lowest) it does seem to fluctuate as I sit there in gear. A few days ago I got a CEL and took it to autozone to get it checked out. The codes they pulled were P0441, P0442, and P0446. A quick google search had me thinking I just knocked a vacuum hose off or something, but I checked every hose several times and can find no issues. I am dead broke, and my manufacturer warranty has expired (i'm at 73k) so I am trying to make this a DIY fix. Oh, and about 3 years ago I had the Idle air control unit replaced under TSB when it was giving me the same kind of idle problems, but hell...a $250 part CAN'T have a measly 3 year life span...can it? I remember cleaning the IACV in my last two cars when they had idle issues, can the same be done to this one?

Thanks in advance for any advice!

Edit: While going through my old post, it looks like my IAC problem a few years ago pulled a code of P0505:
Idle Control System
Malfunction

Different codes...I'm stumped

RedneckwithanxB

heres where your gonna get boned...

Clean your MAF Sensor... its the only thing on your intake that has wires running to it... while your on the intake, find the vac line that runs from it right to the head, as that is prob the cause of your vac leak...

Now come the dumb questions...

How dirty is your air filter?
Have you ever replaced the spark plugs?
Are you running the right type of oil? (Ive made the mistake and run the wrong viscosity before and there was a horrible low idle)

hope some of that works...

trd07tc

iTrader: (-1)

really?

Synthbent715

I will clean the MAF sensor in a few minutes and see if that helps. I have looked at that line you're talking about, it seems a bit loose on the clamps but it doesn't look like its coming off or anything. I changed my plugs and air filter about 30k miles ago, and I know i'm running the correct oil.
Thanks for the help! I will go look now.

Synthbent715

Just checked the hose leading from my intake to my motor, and the hose leading from the intake manifold to the PCV valve. Neither of the hoses seemed to have any cracks, holes, or leaks. The clamps are all firm, but there was a bit of oil in the hoses...is that normal? I reset the computer and drove around for a bit, the idle seems a bit more steady, but with the headlights on and the AC on, my belt squeeks and it idles lower, causing my speakers to pop (even when the radio is OFF) I will need to buy the MAF cleaner later (I only have TB cleaner now)...but I looked at the MAF sensor and it looks perfectly clean.

EDIT: I just changed the belt about 1k miles ago, I tried about 6 different tensions on it and it seemed to squeak less the tighter I got it, right now its pretty damn tight..but it still chirps...

Synthbent715

My damn idle is just going all over the place sometimes, especailly when the AC is on. It will sit there and just jump to 700, down to 400-600-400-700-500 up down up down WTF

JonnyJ27

Did you ever find out what it was? I am experiencing the same problems, same codes were given by obd reader. I have a scion xb 2005 160k mileage, just recently replaced the air filter, I've always used synthetic oil on my car as well. I replaced my gas cap as well, and no luck. My car also feel like it's rpm goes from 500 to 400 when at a stop light, its pretty bad when I turn on my AC.

SatsumaxA

The oil in that PVC hose is due to the PVC valve not closing all the way when engine speed changes. A poorly closing PVC valve is as bad as or worse than an IAC valve needing cleaning. It also allows engine oil to be sucked into intake and contaminate the MAF sensor.... Replace the PVC ($20) rather than cleaning, you really can't tell if making good seal when closing during engine idle cycle..

Synthbent715

WOW! Funny story, I was having some idle issues (this time code is P0505) and while searching for a solution, I came across my old thread from 2010! I absolutely hate it when I find a thread without a solution, without closure...looks like I never came back here to explain how I fixed it. I realize your question is from back in April, but maybe you're still fighting with it...in any case I present you with THE SOLUTION TO THE PROBLEM:

After taking the car to the dealer and getting about $1k worth of stuff replaced (under warranty mind you) the problem still persisted...one day I was looking around under the hood and I saw it; one of the wires on the plug to the vacuum solenoid, right there on the left side of the air box, had actually broken, clean off. I took it out, soldered it back in, plugged it up and the car ran flawlessly for the next 6 years.

I hope this helps anyone who might be having these issues and stumbles upon my old thread here. Sorry it took so long.