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When at idle/revving to ~2k should I be able to feel the individual exhaust pulse from each cylinder?
I've never checked for pulses in the exhaust at 2000 rpm. I tend to doubt they would be noticeable, but I might be wrong. @cardoc ?

I also wouldn't jump to doing anything with the cats until there's better evidence one or both might be faulty.

Look forward to the pic/data from the KOEO test.
 

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2001 VDC/SC One of a Kind
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The exhaust doesn't pulse since Subaru quit using uel headers. since the pipes are about equal length all the way to the collector at the catalytic converter the exhaust tone tends to stay steady.
 

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2011 Outback base 6mt 2.5
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Discussion Starter #23
Does anyone have an exhaust manifold I can borrow to see if I have a clogged pre cat? I know this is a high demand but just want to see if someone has an extra laying around in the Sacramento/Bay Area.
 

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2011 Outback base 6mt 2.5
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Discussion Starter #25
Haven’t confirmed it yet with the back pressure gauge but created an exhaust leak between the exhaust manifold and the block and although loud, I could get it to rev past 5K and was able to pull it into the drive way. :cry::cry:
 

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Haven’t confirmed it yet with the back pressure gauge but created an exhaust leak between the exhaust manifold and the block and although loud, I could get it to rev past 5K and was able to pull it into the drive way. :cry::cry:
Okay, that's a sign. (Is the driveway a steep hill that was a problem to go up before?)

There's two cats, with a joint between. The front one has the sensors; the rear not. As was the case in the threads I linked earlier, it could be the front cat, i.e., the one that is part of the exhaust manifold, or it could be the rear cat (or both, I guess). If the rear one is disconnected, and the test repeated (manifold properly attached to the heads), it might be possible to determine if the front one is bad, or it's the rear one.

I am not very familiar with all the VDC and TC functions. I know that in some situations, the ECM can cut back engine torque. Presumably this involves backing off, or limiting, the throttle plate rotation. It could explain the limited rpm and 69% throttle plate opening, when trying to go up a hill, because the engine is prevented from reaching the normal rpm due to a cat blockage, and the VDC limits the throttle to a safe level. But it wouldn't cause the throttle to be limited to 69% (and based on my recent research into the ECM ROM tables, 80%), when doing the KOEO (Key On, Engine Off) test suggested earlier, because the engine isn't running. Really like to see what the KOEO test shows.
 

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2011 Outback base 6mt 2.5
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Discussion Starter #27
With the KOEO it reads the same, throttle pedal position = 100% throttle position =69%
 

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2011 Outback base 6mt 2.5
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Discussion Starter #28
Trying to source a catalytic converter. I ha e the engine code that ends with NVD but all the engine codes for these end with MXG. Does anyone know the difference in these and will the MXG work for my application?
 

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Not familiar with the three letters of the engine code, but could it be the different your last three letters are for your C.A.R.B emissions compliance (vs., FED compliance for all the others)?

Which cat are you looking for? Have you confirmed it's the front cat that is restricting the flow? Wouldn't want to get a new front cat without making sure it's not the rear that is the real problem. Granted, it's less likely the rear would be bad but not the front (also), but it could happen.
 

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2011 Outback base 6mt 2.5
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Discussion Starter #30
Update: Got the back pressure tester and here are the results. Upstream side has almost zero pressure at idle and while clipping throttle. On the downstream side, at idle gauge was in the yellow (forgot the actual psi) and just got higher as we revved the motor. Ordered a new rear cat and installed it Monday. Problem is gone. Car no longer knocks at 3k, I can actually feel torque coming off the line, not worried about hills anymore and can do hill stats without using the assist. Still confused as to how the rear cat got clogged and not the front but will call it done and move on. Thanks everyone for the help and suggestions with this one.
 
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