1996 Legacy Wagon problems. Fixable?

[SuberYou97]

Hi everyone! I've got my heart on getting a Subaru for my first car, and
I really like this legacy wagon. Its a single mom selling it and shes
only asking $1200! She's really sweet and I like the car but it has
issues. Here's a picture of the engine codes. Looks like some misfires
going on for some reason and the transmission has issues. Looks like its
low on ATF so it might just need a flush and fill. How much/how hard
would it be to fix these things? Engine was rebuilt 15k she says, and it
seems to run fine, asside from a misfire when I shift into reverse.
Thanks everyone! Just let me know if you need more info!

http://s1310.photobucket.com/user/DragonsOfDrakul/media/13819727_1096675567070854_1765315533_zpsxz7mibbs.jpg.html

Here are the written codes if the URL doesn't work.

PO, 500, 740 Speed sensor and TCC CKT electrical, 301, 303, 302, 304
(301-4 are misfire alerts in all four cylinders) , 400 and 743 EGR flow
and TCC CKT electrical. Also it failed air injection? Smog was good.
Also ABS light is on :/

[bakedpotatoechips99]

Had a '95 legacy auto trans with a code 740. That is a shift solenoid for the lockup torque converter for the overdrive.. The issue I had, was after changing the fluid and filter,

 a piece of crud or metal filing likely stuck the solenoid for a while. It eventually freed itself. However, those solenoids can go bad as well. Since it is for the overdrive lockup, even if it is bad, the car still should be fine, it just won't lockup

 it's torque converter in overdrive, and will burn a bit more fuel, but will still be in overdrive, causing no damage to the trans . If you are pulling a trailer regularly long distances on the highway, you might need that lockup, but otherwise I wouldn't worry too much about it, The misfire codes could be a number of things, and unless the rings and or valve guides are totally shot, should not be monumental to repair. Subaru's are prone to leaking valve cover gaskets and or spark plug tube seals, which can leak oil around the spark plugs and their wires, essentially shorting them intermittently. You need to pull the plug wires and look inside of the spark plug tubes with a flashlight and maybe a flexible mirror for one or two of them (spark plug tubes) to see if there is oil pooling in there. You might get an idea of that by simply looking at the plug boots for excess wet oil on them. However, sometimes this situation goes away when the engine gets hot enough to burn off and evaporate the oil and the misfire can go away for a while, only to return later. It all depends. Then, of course the standard things to check are the plug wire resistances with an ohm meter, or, simply replace the wires if you don't have one.The ignition coil can be checked for primary and secondary resistance. Finally the igniter, is a small electronic module ( black, and the size of a match book) that sits on the "dog bone" in the middle of the firewall, and has an electrical plug going to it,

  with 4-6 wires or so on it's harness plug. This amplifies the signals for the spark/ignition.That can deteriorate over years. Those about hundred and fifty, but  used ones can be obtained on ebay for a song. Those igniters also have a metal heat sink on their bottom or mounting contact area, and are held down with 2 screws.

  You want to use some die electric grease under them, and sand off the mount area on the firewal/"dog bone" where it mounts to (if there is rust or crud on the firewall/"dog bone" when you remove the old igniter), Sanding down the mounting area to make way for a replacement igniter,before applying the die electric  grease and mounting down the new (or newer/better used one) igniter. This enables it to remain relatively cool inside as it works to assist the ignition system. If you just remove the old one, and screw down another one, it will likely work, but can get hot and not last as long as if you use the die electric grease and make sure that you use some 100 or 150 grit sandpaper

 for the engine bay so the metal pad on the replacement igniter can dissipate it's heat  to the firewall mounting area. Prior to purchasing any ignition parts, you can get a new set of plugs and simply connect them to the plug wires with all 4 plugs out of the engine, but the plug's metal bodies touching ground or metal on the engine some where (kind of wedge them into external areas where they are grounded), even the aluminum intake manifold, and with the ignition on, either have someone crank the engine, or use a screwdriver or remote starter or wire with 2 alligator clips to crank the starer while observing the spark at the plugs while the engine is cranked over (ignition on!). The spark at the plugs should be at least slightly blue in color. If it is faint and yellow, the spark is weak, and will misfire inside of the engine, or not even start in some cases. Lastly, a misfire can occur from oil getting into the combustion chamber/cylinder, from badly worn rings and or valve guides and or valve guide seals. You would be able to see this if you remove the old plugs, and spot a wet oily spark plug firing tip. A new ignition coil, new plugs, and a used igniter is what I just installed in the '95 legacy, as it would not even start prior to these new parts. It had been badly misfiring and stumbling. The valve cover gaskets and spark plug seals were not the problem on this one. It burns some oil, but is able to run smooth still. Spark plug heat range is also something to consider for an older engine. A "hotter" set of plugs can be installed if oil burning is excessive, and this will sometimes enable an older engine that burns oil to run smoothly regardless of worn rings and or valves and seals, which would cause a misfire for either standard or for "colder" plugs If it does not burn oil, you can install a "colder" set of spark plugs for the summer, to prevent pre ignition/pinging.

  Finally, if you replace the coil and or igniter, you have to make sure that even though you might plug them into the wiring harness in the engine bay, that the pins are/were not bent, or one or more wires/pins pushed back or otherwise not making contact, and you may want to use some electrical contact spray cleaner for any electrical connections like that prior to plugging them back in, to ensure that your new parts purchases, and labor do not go to waste from a faulty connection when plugging them into the engine wiring harness. 

Edited July 22, 2016 by bakedpotatoechips99