My husband and I own a 2006 Baja w/ turbo. It has run great for a while, has some past issues that we thought were resolved shortly after purchase. We were currently debating on trading in for a newer subie that fits our needs better but have hit a major snag. It started throwing codes at us. We have gotten the PO303 code with no luck chasing down the issue.

 

We changed the spark plugs, ran great for a few days, then code repeat. Change coil, ran fine for a few days, code repeat. Replaced cyl3 injector, ran good for a day. Then once again, code repeat. We have chased every rabbit hole we can think of and it seems to fix the problem for a very short period then poof, back to square one. 

 

My husband even tried unhooking the exhaust to to see if maybe we were catching the code from something in the cad converter. No luck. Now its back to doing exactly what it did when we first got the code. Rough idle, but has now acquired the problem of dying out when the clutch is depressed..... Any ideas or approaches you folks can think of? We dont have the money to dump a lot into this trying to chase down every possibility, but unless we have it running well, we have nothing to trade in to get even close to getting what we were after. Questions, comment, ideas are so very welcome and this point.... we have become extremely stressed over this issue.....

Have you done a compression test?

Not as of yet. We were contemplating that option but I wanted to see what other options we have to look at on this before hand.

You might also check for intake air leaks.

A compression test doesn't take very long and either confirms or rules our that problem. Harbor freight sells compression testers for around $30.

HI,

 

 

P0303 Code - Cylinder #3 Misfire

Read more at: http://www.obd-codes.com/p0303
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Miles? Recent maintenance? Original Turbo? Did you replace the seal on the Valve / Rocker Cover around the spark plugs? Oil can leak down and cause your issues....but you should've seen that by now.

 

If you're going to do a compression test, I'd add a Leak Down to that list and a smoke test to rule out leaks as Cougar stated. Yes, it's $$ but then you know the health of the block AND heads.

 

If you don't have the $$ to fix this, you're better off staying w/a NON-turbo Subaru in my opinion....These older, hi-mileage Turbo Subarus are $$ pits...and Yes,  that's from experience.

 

And if you haven't, go look on the other Subaru sites such as SubaruForester.org and NaSiOC.com. Your '06 has the same engine - exactly  - as the '06+ Forester XT and WRX, and very similar to the STi.

 

Misfire codes on the turbo models are .....a  pain.

 

GL,

Td

+1 to what they said.

check valve clearance too - that's essentially free, just labor.

 

i've been wanting to ask this anyway - what happens if the igniter gets wonky?  can it throw a misfire code or would it be a pair of codes or all of them?

 

if you're frustrated I'd spend some time googling cylinder misfires in 00-09 Subaru's and read everything you can, i'm betting you'll find a few non-typical (not spark plugs, wire, or coil pack), that might give you some direction.  the 00-09 4 cylinders are all similar enough (all the blocks are interchangeable even the headgaskets are interchangeable) that the info should help.

Edited July 28, 201510 yr by grossgary

'dropped' valve guide? I think you have to drop the ex. mani. to inspect for that.

 

http://forums.nasioc.com/forums/showpost.php?p=26147542&postcount=5

 

https://allwheeldriveauto.com/subaru-service-seattle-dropped-exhaust-valve-guides-explained/

Any tips on a good way to find a vacuum leak??

if the car has an uneven idle, you can spray carb cleaner around the vacuum lines and the intake manifold while it's running. listen for the engine to perhaps smooth-out or otherwise change it's sound/speed. Some people have even used propane but I'd think the fans and other air movement would make that trickier than directing a stream or spray of a flammable liquid.

 

you buy/rent a vacuum gauge too - if it shows low, go around the engine compartment wiggle the vacuum lines while watching for a change in the gauges reading.

 

Edited July 29, 201510 yr by 1 Lucky Texan