Stromung Catless Downpipe

[chuglobal]

I purchased the Tanabe SRM and Stromung catless dp at once from Brett @ Renick Subaru. I was very concerned on throwing CELs due to removing both Cats in the uppipe and downpipe. I talked to both Brett and Scott ( owner of Stromung ) in great depth asking 100+ questions. Brett stated that there are people in Ca. who have also removed both the Cats in the uppipe and downpipe and have NOT thrown a CEL. Scott stated that the test cars at Stromung are still running the factory uppipe but w/ the second two Cats, downpipe and midpipe, were removed and NO CELs. Scott ask that I call him back once I get my setup and run the WRX for a while and fill him in on the situation.
Well as most know I got a CEL code P0546 in <12hrs after the downpipe install. I thought it was my imagination however I reset the ECU and the same code came back. Well after looking and asking around on IClub I found out that it had to do w/ the EGT sensor in the uppipe. There were 2 reasons:

1. EGT sensor just happend to die after the downpipe install; w/ my luck I would be surprised but I highly doubt it.
2. Due to the catless uppipe and now the catless downpipe the EGTs are significantly lower thus the ECU thinks the EGT sensor is not reading right thus causing the CEL.

I'm not surprised but I still think it's the later of the 2 ideas. I've talked to may people and they agree w/ me. I'm not too worried since I do have an aftemarket EGT setup in the exhaust manifold so I've done the 2.2 kohm mod and NO more CEL . The cat inefficiency code P0420 that I expected was never thrown ... weird. I've even done the MIL fix but I might have not even needed it.
I could notice a HUGE power increase w/ the catless downpipe. I feel the catless uppipe and downpipe is the way to go for cheaps mods for the WRX. The Stromung welds was nothing fancy as compared to the Vishnu welds however for a <$200 downpipe I'm not complaining if it does its job. Is paying $515-700 for the Godspeed and Vishnu downpipe really worth the $300+ difference. I do appreciate Scott's time and I hope Scott will continue to provide the WRX community w/ value added products at lower prices.

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[frankramo777]

got your #, just been super busy, question did you ask dude at stromung if our cars will pass emissions with just one cat?? did love to do exhaust work, but not if ive got to put all the stock parts back to get a pass report at emissions.. any thoughts??

[chuglobal]

I replied to your PM. You should still give me a ring sometime.

[chuglobal]

I did all my mods in steps and not all at once. I started w/ just an uppipe and no CELs. Then went w/ a MBC & gauges and obviously no CELs. Then installed the Tanabe SRM Cat back and no CELs. However once I installed the catless Stromung downpipe I got a CEL in <24hrs. I got reset the code and it came back. I got my code pulled at a local Firestone and it was P0546 and then another time by a person on IClub and it was still the P0546; so the only variable that changed was the catless downpipe. I also noticed how my EGTs dropped w/ the downpipe. Theory goes since I installed the catless downpipe and then it threw the P0546 CEL the sensor was reading that the engine was running cooler than normal and thus the CEL.

[westy66]

ive recently done the Stromung catless DP (i have stock UP)... i had a MBC first, and then did the DP and Samco hoses. within 24 hours i got a CEL. i reset (pulled fuse) the ECU and it came back two days later. my friend was going to pull teh code, but his friend has his OBD stuff. i assumed that the CELs were from the 0420 (cat innef.) but am now thinking they are from the low EGTs. if so, the MIL fix wont help this then? how do i do the " 2.2 kohm mod " if my CEL is the 0546?

Bob

[wrx2]

Please answer Bob's question. I also wanna know. Anybody?

[LatinWRX]

I wanted the Stromung DP but i guess the consensus is stay away?

[westy66]

i dont get it.. i had read a bunch of different time here that the Stromung catless didnt cause any CEL's. now, i am reading all over about the low EGT CEL are most turbo-back exhausts cat's in the DP to maintain the heat?

Bob

[nhluhr]

Originally posted by westy66
how do i do the " 2.2 kohm mod " if my CEL is the 0546?

Bob

I assume you can locate the OEM egt probe. It's the one that sticks out of the uppipe. Anyway, remove the probe from the uppipe and replace with a short bolt (12x1.25 threading). Then unplug the probe from its wiring harness and stick the two ends of a 2.2kohm resistor in the plug where the probe used to plug into so that isntead of the circuit being the probe, the circuit is the resistor... get it?

[westy66]

well, i pulled the codes last night and found out they are the 0420's.... "Cat Innef." so i wont need the resistor fix, but i think ill look into the MIL Elliminator from Pony Express

[wrx2]

So, does 2.2kohm mod fix CEL 0546 only? Is it possible that I have both Code(0546 and 0420)? If so, what kind of mods can cause this problem?

Choi

[chuglobal]

Yes the 2.2 does fix P0546. I never got the P0420 but I already installed the MIL Fix from Pony Express.

[MackDaddy]

I had an ATR up-pipe on for over a month, with no CEL's. Installed Stromung's catless DP last weekend, and did Ponyexpressperformance.com's MIL/CEL eliminator at the same time. Works like a champ.

I've got the following as well:

Samco IC hoses
Stromung rear axle section
K&N panel filter in OE airbox, no resonator
Forge 100% amto dump BOV
3/16" FEBC solenoid restrictor mod
4 point grounding mod
STI hoodscoop / Quantum Racing splitter
Stock OE 3rd cat / mid pipe

Anyone thinking of getting the Stromung DP, do it. Just use the MIL fix mentioned above.

HTH - Jim

[chuglobal]

2.2 kohm = P0546
MIL = P0420