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Replaced IAC valve.

Code 24 still coming up.

So something is wrong, and my problems sound a lot like Matt's when he's got his 02 sensor hooked up.

I'm not sure what to check now. Still throwing the IAC error code, but the IAC is new.

What do you guy's think?

Is it the right sensor? If the turbo sensor is different and you got the N/A (dealer error), maybe it's giving messed up readings.

Steve

I dont htink the NA sensor would have fit had he gotten that one. He also would have instantly noticed the difference.

The angles are different for the hoses on the NA model so I don't think it's the wrong one.

Could it be something in the wiring?

My O2 sensor problem is similar except my rpm's aren't going high like Phils. Mine idles really bad when the O2 sensor is hooked up and my vac readings go really low. My fuel trims go to around -20% which is full lean too. It idles at the regular 500-750 rpm but will stumble and almost stall because the RPM's drop to like 3-400 rpm. I usually get a code 24 when I try to use the O2 sensor too but I won't get a CEL. Mine might be the O2 sensor wiring or the ECU, I'm not sure yet, but the fact that I can't get my codes to clear out of R-mode makes me wonder what's up with my ECU...

Yea, I idle wicked high (1200 to 1800, when it is around 1k, it oscilates between 1k and 1200 and shudders violently).

I don't know how to check the wiring, any ideas? Multimeter?

Matt - Maybe you can come over and take a looksee and see if you can notice anything I might be missing.

I'm about to go pull the negative terminal and reset the ECU, then go for a drive in R-Mode and see what goes on.

Heh, the two of you should swap ECUs and see if you swap problems.

Haha, ya, maybe we should.

Phil- How long does the car have to run before you get the CEL? I'd do a D-Mode check along with the R-mode check. That way you know what's stored and what's actively going wrong.

honestly you should, it'd only take like 10 mins max to do it.

CEL is on all the time now

How hard is it to swap ECU's?

If my ECU is toast, then I'm in for some problems. But here we come standalone if my ECU is dead.

ECUs are easy to remove/install:

- Remove the trim panel above the driver's knees with a Phillips head screwdriver
- Disconnect the four yellow connectors from the ECU by pushing the tabs in and pulling towards of the right of the car
- Use a 10mm socket on a long extension to remove the two nuts holding the ECU in place
- Push on the studs of the ECU to disengage it from the mounting brace and push it towards the right of the car and wiggle it out.
- Installation is reverse of removal.

Oh, I should just cover my rear by saying this:

In theory it is possible for a bad wiring harness to harm an ECU. A worst-case example is when MK used a screwy mix of NA and turbo wiring and fried his first EJ22T ECU. I doubt you guys will have any problems of this type because the sensor lines tend to be well protected inside the ECU (MK was actually shorting +12v and ground through two ground pins of the ECU), but I should mention it anyway. If they were my cars, I'd swap the ECUs.

BAC5.2 wrote:Yea, I idle wicked high (1200 to 1800, when it is around 1k, it oscilates between 1k and 1200 and shudders violently).

I don't know how to check the wiring, any ideas? Multimeter?

Matt - Maybe you can come over and take a looksee and see if you can notice anything I might be missing.

I'm about to go pull the negative terminal and reset the ECU, then go for a drive in R-Mode and see what goes on.

was just notified of this:
http://www.geocities.com/kuleshoff/IAC.htm

That looks like it's basically just a copy of what's in the Haynes or Chilton's manual.

The factory service manual (see link in Josh's post in Stuff You Need to Know) has some basic checks you can do though.

Well, I reverted to stock intake gear (pre-turbo resonator) and tried the connector ECU reset.

I must not have done it correctly though, because it didn't do anything. No 1/2 second flashes or anything, after about 5 minutes, the CEL just flashed 24 over and over again (as if I was just running in R-Mode).

I just pulled the negative terminal and I'll see what happens there. If that doesn't solve it, then I don't know what else to do about it

Did you only have the green connectors hooked up or did you have the green and black hooked up when you tried to clear the codes? If it was just the green then that is D-mode. If it was D-mode and you were getting a code 24 then you're IAC is definitely not working correctly. I still say maybe you got a fautly part. I'd go to the dealership where you got it and ask some questions. Maybe they can get you going in the right direction. If you have an ohm meter I'd check the wiring harness connectors like Hardy listed.

It was green and black both connected like Josh's site says.

I'm about to go reconnect my battery and let the car idle. Then I'll go for a drive in D-mode. If it still doesn't work, then I will DEFINATELY go back to the dealership.

Does it ever idle normal? Could your idle screw be out of adjustment? I'm just throwin' stuff out there.

Nope, never idles normal (which should be 700 +/- 100).

Just reset the ECU (pulled negative terminal) and as soon as I restarted the car, there was a CEL.

Dropped it into D-Mode, and went for a ride.

Codes: 12, 24, and 45 came back.

That's Starter Switch, IAC, and Pressure sensor and pressure exchange solenoid valve.

The 12 code, I don't understand (but would explain why it had a CEL RIGHT at start up).

The 24 code pisses me off, because I JUST had the IAC replaced.

But the 45 code is the kicker. If the pressure sensor is dead, then that could affect the IAC, right?

So... looks like I need to take a trip to Subaru tomorrow and get a new pressure sensor and exchange solenoid valve.

Something odd though, in D-Mode, the car idles even higher! Regularly at 2000 RPM, surging to 2500 (holding there).

What do you guys think? Where are the pressure sensor and the exchange solenoid valve located?

Matt - If I can get this taken care of this week, then I'll have an envelope for you before you come back down next week. Don't sweat the part we were talking about though. I've got 600 miles left before I want to do any work like that.

I just went for another drive, and D-mode only pulled 1 code, 24, IAC. I tried the clear-memory thing again (plug both connectors in and drive for 1 minute until it flashes that the ecu is clear). 1 minute after taking off, the CEL starts to flash, not the memory-clear code, but 24. And in D-mode, with the clutch in, shift into any gear (clutch still in) and the rev's jump up 400 to 600 RPM.

This is starting to piss me off .

You still haven't tried the scan tool, have you? I really think it could be useful to compare your readings at idle to other turbo owners'.

I've got a laptop to use downstairs, maybe I should go rip apart a printer cable and make me the scan tool.

Vikash, check your PM's. I sent you one.

Yes, you should go rip apart a printer cable and make yourself the scan tool. You can even just poke wires into the yellow connector, since you're not gonna be moving your car while taking readings. And you can connect the PC's ground to a more convenient ground on the car than the ground pin of the yellow connector if you want to make it even easier.

I replied to your PM just before reading this.