Subaru Outback engine issue (possibly head gasket?)

[oberon_1]

Thanks GregW and sunsprit.
On one issue I disagree: I do want and need a detection and diagnostic system on board. Its essential. The industry did not "find it fit to pursue" because politics and financial interests. But since so many cars have problems that are hard to diagnose (and average cars shops have no real expertise), it is an essential tool for the car owner. Otherwise, you can step into a shop that misdiagnosed the cause and the problem.
As you correctly observed, "check engine" is an improper name for the function it fulfills. Some automakers added even more codes to this single warning, causing additional misunderstanding. In our age of everything computerized, keeping a warning system that belongs to the 70s, is simply wrong. Car racing and the aircraft industry solved these decades ago.

[GarageLogic]

Originally Posted by Prple

I recently bought a 2000 Subaru Outback Limited with 117k miles on it. Bought it from the original owner with all records. Headgasket was done 22k miles ago (3 years ago) but I am worried that it is going out again... I took it in because there was exhaust coming in through the cabin (would smell when first started up car and when stopped; also smelled like something was burning when I got out of the car). Took it to the shop and was told that it has an oil leak and that the exhaust gasket was leaking. Got new valve cover gasket, spark plug seal, valve cover seal washer, exhaust gasket and oil to fill to capacity per manufacturer eo. Now the check engine light is on, about 50 miles later (scan says needs new sensor; it has a brand new catalytic convertor)... Also, when I took it into Firestone for an a/c refresh a few days prior, they recommended new radiator hoses, coolant system services/flush with sealer and spark plug with fuel system cleaning.. After doing some research online, I feel like the headgasket might need to be done again; what do you think?

First... Unless the head gasket replacement wasn't done properly, you shouldn't be looking at another one. The most obvious tell-tale sign would be that you're losing coolant, and the car is overheating.

Second... The repair done by the shop sounds appropriate.

Third... You need to know exactly what trouble codes you're dealing with. Also know that many OBD2 codes head you in the right direction, but don't actually say, "Your upstream O2 Sensor needs to be replaced." There's a certain "art" involved.

Fourth... Do not EVER take your vehicle to Firestone, unless you have NO choice.

[GarageLogic]

Originally Posted by Prple

Apparently the scan indicated that it is due to oxygen sensor..
Looks like the oxygen sensors were done at 97k miles at the same time as the headgasket (3 years ago, 22k miles ago). Catalytic Convertor was done 1000 miles ago.
It would be great if it really only needs oxygen sensor(s).

I'd be curious to know the exact code, because sometimes (a P0171 for instance) a code indicates that the O2 Sensor(s) could be one of the problems.

Also, do you know which O2 Sensor was replaced? Were both done? Also, if cheaper after-market sensors were used, they can cause all manner of problems, including early failure.

[GarageLogic]

Originally Posted by oberon_1

Thanks GregW and sunsprit.
On one issue I disagree: I do want and need a detection and diagnostic system on board. Its essential. The industry did not "find it fit to pursue" because politics and financial interests. But since so many cars have problems that are hard to diagnose (and average cars shops have no real expertise), it is an essential tool for the car owner. Otherwise, you can step into a shop that misdiagnosed the cause and the problem.
As you correctly observed, "check engine" is an improper name for the function it fulfills. Some automakers added even more codes to this single warning, causing additional misunderstanding. In our age of everything computerized, keeping a warning system that belongs to the 70s, is simply wrong. Car racing and the aircraft industry solved these decades ago.

The typical car owner is absolutely nowhere near as knowledgeable as you, nor do they care to be. They'll either just drive the car until it dies (regardless of warning lights), or they'll take it to the dealer for any and all issues.

But you are right. Vehicle manufacturers could do a better job of making their vehicles' issues more easily diagnosed. But they have no real incentive to do so.

For what it's worth, you might want to look into some smartphone apps. The ELM 327 and Torque Pro are some surprisingly good - and cheap - diagnostic tools.