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Glowing catalytic converter in 02 Outback


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02 Outback with EJ25 (now EJ20) and 365k on the body.

 

My buddy said his motor had a head gasket leak. Motor was a junkyard motor of unknown mileage installed about a year ago. Was puffing constant clouds of white smoke and he said was also taking coolant. I helped him install a low miles <60k JDM EJ20 SOHC yesterday. We didn't finish until well after dark. Started the car and it runs smooth.

 

White smoke continued. I figured it would dissipate after a bit. Would burn off stuff from sitting and whatever was left in the exhaust from the last motor. it went down a little but after about 10 minutes at idle I popped the hood and saw the ring around the 02 sensor and the front of the cat were glowing orange. We shut the car off to let it cool off. Only drove it 1/4 mile to the parking spot.

 

Motor seems fine and is not running hot. White smoke billows out the exhaust. Cat and o2 ring glowing. No  CEL yet but may pop up. Not misfiring as best I can tell. Am I looking at blocked cats? Bad injectors? Coil?

 

Wanting to have a game plan before throwing any parts at it. I have spare intake manifolds and associated stuff. Cats are expensive.

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One of my nephews a few years ago returned from a 200 mile trip. Later stated the car was "running rough". Parked the car inside the garage and went to bed. An hour later fled the house because it was on fire. House was a total lose. Fire marshal determined an overheated CAT started the fire. 

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unbolt the exhaust manifold from the engine and run it?

 

someone on here or subaruoutback just had a bad converter - they did exactly that and the car ran fine.  might want to find that thread and see what they're symptoms were, i don't recall exactly?

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Cats really only glow because there's too much unburned fuel being run through them.

If the head gaskets were bad on the old engine and coolant was being burned, the cats are contaminated and are probably partially blocked which will cause overheating of any unblocked sections as all of the exhaust tries to push through a smaller area of the cat.

 

Make sure the fuel pressure regulator is not leaking into the vacuum line. Make sure none of the injectors are leaking, especially if it has the side feed injectors because the o-rings around the injector base can leak fuel into the manifold.

 

Glowing cats are toast. They need to be replaced, but check the injectors and FPR first so you don't burn up the new ones.

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  • 2 weeks later...

Trying to chase this down now that I have my new code scanner.

 

Pulled codes P0507 and P1507 both dealing with idle air control. Swapped a used IACV motor. Replaced the throttle body gasket with a used one as well since the throttle body was slick and wet. Seems like oil/coolant or both may be getting in somewhere? suspected either a leak or failure. Cleared the codes and started the car. Still white smoke. CEL came on within about 20 seconds with the p0507. Idled high and dropped to normal as soon as the CEL came on.

 

What next? I have about 3 full intake manifolds so I can take a shotgun approach to some things. Fuel injectors, coil, plugs, fuel pressure regulator..... Anyone have any other suggestions or starting points. I feel responsible for getting this car on the road since I told my friend I'd help him with the motor swap and save this thing.

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 Was puffing constant clouds of white smoke and he said was also taking coolant. I helped him install a low miles <60k JDM EJ20 SOHC yesterday. We didn't finish until well after dark. Started the car and it runs smooth.

 

White smoke continued.

 

Same symptoms before and after the job suggests whatever was replaced wasn't the issue to begin with.

 

1.  what parts are "the same" on both the original and "new" engine?

 

The intake manifold?  If so - I'd swap that or look there to repair.

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