Possible head gasket blown?

[Schlitz]

Hey all, I currently own a 04 Wrx with intake/exhaust. It has around 82k miles and I bought it used. I have only had a few small issues, maf sensor went bad, had a couple check engine lights due to lean fuel mixture. I had it smoke tested and was told there were no leaks and that the lean mixture was due to the intake/exhaust being installed without any tuning done to the computer. I would wash my car then get an engine light right after, got the code ran and it was caused by the MAF sensor which is right beneath the scoop. It went away when the sensor dried out I guess. I eventually sprayed some electra shield on the top of the connector to prevent moisture/water getting into the connection. This seemed to solve the MAF issue, but I was still getting random lean fuel mixture check engine lights. That also went away as I think driving it at high RPMs in first gear is what caused it to come up. So a few months down the road and I get another random check engine light after driving to work when it was extremely wet outside (raining heavily). I got that code ran and it was the lean fuel system again. I guess the MAF sensor has something to do with that? I then tried to insulate the female side of that connector plug and the one right above it ( sitting right beneath the hood scoop) with this mini tube of dielectric grease. I then reset the computer myself by unplugging the neg batter cable. I did this all during my lunch break that day.

After work I was driving home from work on a freeway going around 65 mph for around 15 minutes. I took my normal exit and came to a stoplight. At that point I noticed some white smoke come out from under my hood. I didnt notice any overheating, the idle was sticking at 1k for a second when stopped but then dropped. I drove it a couple blocks to check under the hood. I saw antifreeze pretty much everywhere. I then had it towed to a small muffler shop near my house and they told me I had a blown head gasket. They then quoted me 2300.00 for the repair. They said they did a compression test, where they started the car, gave it some gas and antifreeze bubbled out the radiator. I am curious if anyone knows another reason this may be happening. I didnt see any overheating on the dash gauge and its an 04 with only 82k on it. (oh also forgot to mention, whenever I used the heater the idle at a stop would randomly jump a little bit, just obvious enough to hear) I was told its because the AC always is running and its just something these cars do.

Thanks for any advice!

[UEDan]

Maybe it was the untuned intake/exhaust that was mentioned in your first sentence.

1. An untuned intake will let in too much air, causing lean condition.
2. An untuned downpipe will cause you to over boost, causing a lean condition.
3. Your car threw a code during the rain because colder air is denser than warmer air. Thus allowing more air in. And we're back to #1
A lean condition can melt pistons. Your maf is fine.

Sorry about your car.

[SD_GR]

Get a second opinion.

If it's the head gasket I would prefer a Subaru specialist perform the labour. I'm not saying a dealer; an independent specialist will be more than capable of doing everything correctly.

First though find out for sure what the problem is.

[EndlessSea]

i think for the first time since joining this forum i completely agree with what SD_GR stated.

get a second opinion, and have a qualified tech do the work

[Mikie13]

So why weren't you running a proper tune? That's your first issue...

And yes as SD said...have a reputable Subaru capable shop do the work. Not a random muffler shop.

If you have coolant coming out of the radiator, wouldn't that indicate a busted radiator? Radiators popping is a known issue in older WRXs...

The lean bank codes can also be caused by exhaust leaks as the rear 02 sensor isn't picking up what it's supposed to be (I'm dealing with this now myself).