First off I would like to say hi and thanks for any help you all can offer! I have looked all over this forum and don't see an issue quite like mine. If I am posting this in the wrong spot, or there is a thread already made that will help me out please let me know.
So my wife's BFF just moved to Las Vegas from Washington State. She has a 1999 Subaru Legacy Outback with the 2.5L DOHC motor in it, that she recently purchased before her move. The seller told her that they did a full tune up just before putting it up for sale. After she got here to Las Vegas she took it to get smogged so she could get NV plates for it. It failed the smog test. They gave her a list of the OBD2 codes (too many to list). Basically misfire in every cylinder, knock sensor, and a few others. And told her it would cost about $1,000 to get it fixed. That's where I come into the story. I looked into it and decided that I would help her out.
What I did 1st:
1) Full tune up, consisting of new NGK plugs and wires, pcv valve, oil change, air filter, gas filter and ran some Lucas fuel injection cleaner through the system.
2) Replaced the knock sensor (per the OBD2 code)
When replacing the "NEW" spark plugs I found that it had 3 different spark plugs in it.... and that the #4 cylinder was cross threaded.
What I did 2nd:
1) I went and bought the proper sized tap and fixed the threads and finished the tune up.
2) Reset the CPU.
After a couple of days I rechecked the OBD2 codes. At this time we found only 2, P304 and another that I can't remember (No check engine light present). After some tinkering I found little to no spark in the #4 cylinder and decided that the coil pack was bad.
What I did 3rd:
1) Replaced the dash light bulb, found that someone had removed it so it didn't show that it was on when selling it. They couldn't even be nice and put the little bulb holder back into the instrument panel (What nice guys).
2) Replaced the bad coil pack with a new one
3) Reset the CPU
After a couple of more days I rechecked the OBD2 codes and found just one, that evil P304 code! Not sure where to go next I told the owner that I would have to do some more research on it. She decided to take it to a Mechanics shop and have a full diagnostic done on the issue. $100 later he told her that cylinder #4 had no compression and that it was a bad motor. She called me at this time to let me know what he had said, I had her ask if it could have to due with the spark plug not being seated properly due to the previous cross threading issue. He said "Nope" it needs a new motor...
Now if this had been any other cylinder than the one that had been cross threaded I would have been less likely to question his findings and opinions.
Please if you have any ideas or suggestions please let me know, also if you think that I am barking up the wrong tree I would like to know that too. Again thanks for any and all help you may be.
