OB99W

I'm glad you're making progress. All the codes you listed, including the ones for the O2 sensors, are generated when the green connectors are coupled. Pull them apart, clear the ECU memory, and they likely won't recur.

A reply to my previous post could be useful, but I'm going to make an assumption. The codes you're seeing are typical when the green test/diagnostic connectors under the dash are coupled together. For normal operation, they shouldn't be -- disconnect them.

Does this car have an auto or manual trans? With that info, I can give specific suggestions.

Are you referring to http://www.ultimatesubaru.org/forum/showthread.php?t=95881 ?

They can be found on eBay, and elsewhere. Google 'cv axle boot band tool' for some links.

I could individually address some of the issues you've raised, but the first thing I'd suggest is to carefully verify that all the electrical ground connections were correctly made when the 'new' engine was installed. Bad grounds could cause many of the problems.

You're welcome.

Isn't it below the lower portion of the dash, at the left, beneath the hood release?

More on airbag inspection: http://www.cartalk.com/content/columns/Archive/2001/March/05.html

Depending on your frame of mind, you might find the following thread either informative or entertaining: http://www.ultimatesubaru.org/forum/showthread.php?t=65967 I'd start by asking your dealer what they inspect.

That's on the low side, especially if you don't use thread-locking agent. If the crank pulley loosens, it can cause significant damage. However, until you've run the engine and determined that all seems okay, I wouldn't go any higher than what Alldata says, so that you won't have a hard time loosening the bolt if you need to. Once you know that things are working correctly, you should probably aim for about 125 ft-lbs, but be forewarned that some forum members have managed to snap off the bolt at below that torque. You might want to use the search function and read some of the threads before proceeding.

Yes, and it's also important that it takes about the same number of engine revolutions to reach relatively equal readings. For example, even if all four cylinders eventually peak at 175 PSI, with three of them requiring four compression strokes to achieve that but the remaining one needing seven, that indicates a problem.

How about a general rule of thumb (assuming you do know the compression ratio)? Things such as valve timing, cranking speed, warmth of the engine, altitude, etc., affect the pressure, but the following will give a 'ball park' figure for a 'typical' engine in good condition. Multiply the compression ratio by 18. For the 1.8L, with 9.5:1 compression, that results in 171 PSI.

See: http://endwrench.com/images/pdfs/ABSInsiderEWFall05.pdf

Assuming the engine hasn't seized or otherwise self-destructed, there's certainly a possibilty that you're facing a hydrolock. It seems that before trying all kinds of alternative approaches, it might be prudent to pull the spark plugs.

Since the CTS is a common failure item that can cause what you're experiencing, why not look at its operation? There's a fairly 'low-tech' way to determine if the CTS is doing its job. If you have access to an ohmmeter, and can get to and unplug the connector, then taking resistance measurements of the CTS is probably a good starting point. See the following thread for more info: http://www.ultimatesubaru.org/forum/showthread.php?t=86546

What Cougar wrote is good info. The only thing I can add is that an O2 sensor's heater changes resistance with temperature, since it isn't needed once the exhaust system reaches operating temperature. They typically draw about 2 amps when 'cold' (ambient temp) -- the resistance is around 6 ohms then, and it goes up significantly when hot.

The mixture I've been referring to is that of the air/fuel. It has nothing to do with the coolant antifreeze concentration; 50/50 coolant is fine for summer, and for all but the most severe winter conditions. As long as there are no air pockets in your cooling system, the level in your coolant reservoir is about right. To better understand how the air/fuel mixture is determined, see: http://endwrench.com/images/pdfs/Fuel.pdf In particular, note the correction factors listed on page 11.

A defective CTS can cause the problem, since the ECU reads it to determine if the engine is cold and the mixture needs to be enriched. If the data is wrong, the mixture can be too lean for a cold engine, and it doesn't generate a trouble code because the ECU doesn't know it's being 'lied to'.

See my reply #10 in your previous thread on this topic: http://www.ultimatesubaru.org/forum/showthread.php?p=796067

It means it's the rear one, and specifically that there's a problem in its heater circuit. That could be caused by a failure of the heater inside the sensor itself, or just a poor (loose/corroded) connection.

Larry -- 1) Warm the engine, then verify if you can see the EGR valve operate if you rev the engine. 2) With the engine idling, disconnect the vacuum hose at the EGR valve, and apply some vacuum to the valve (just a few inches should be enough) with either a hand pump or even sucking on a length of hose by mouth. The valve should operate, and if the exhaust passages are okay, the idle should significantly falter. Let us know what happens in each case.

Sorry, I didn't mean to oversimplify. Yes, there are obviously two cylinder banks on the fours, but since they share a single front (and rear) O2 sensor, any such code is for Bank 1 only -- a code for Bank 2 isn't generated. My point was that the bank number isn't helpful in this case, the sensor number is what's important. A P0130 code, for example, would be for Bank 1, but so would P0135, even though one is for the front and one for the rear sensor.

'Bank 1' doesn't indicate whether it's the front or rear sensor, since on a 4 cylinder Subaru, there's only one bank. (It is more common for the front to fail, but not necessarily.) Also, there are oxygen sensor codes that can indicate problems with other than the sensor itself. What's the actual code (P013x or ...)?

See:http://www.ultimatesubaru.org/forum/showthread.php?t=95694 and http://www.ultimatesubaru.org/forum/showthread.php?t=95701