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Old 09-11-2005, 05:01 PM   #1
Scooby Newbie
Member#: 74655
Join Date: Nov 2004
Chapter/Region: Tri-State
Location: ny
97 legacy outback

Default engine hesitation...clogged cats?

So I just completed the dreaded HG replacement and did the timing(2.5 dohc). I connected everything back up and it started right up. Everything was fine except for a CEL . I borrowed my friends stock ex. manifold and his rear o2 sensor. I switched these in and passed inspection. on my way home from school I noticed a hesitation only on my first launch. after that it would be fine but would happen again if you let it sit for 5 minutes. I then put my borla ex manifold back on and it still did it. I went to autozone to get a new o2 sensor and they dont have it in stock. that next mourning on my way home from work i heard a pop and my exhaust sounded like it fell off. I pulled in my driveway and looked under the car. I noticed my front o2 sensor hanging there with out any threads on it. now i need to get 2 o2 sensors and probably the 2 front cats. Would a clogged cat cause the front o2 sensor to pop out? could the hesitation be caused by that clogged cat or is it completly different? I was also wondering if there is any aftermarket cats for the 2.5 (legacy)? thanks Andrew
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Old 09-11-2005, 05:22 PM   #2
Scooby Specialist
Member#: 87103
Join Date: May 2005
Chapter/Region: TXIC
Location: San Antonio, TX
2005 Impreza RS RWD
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A clogged exhaust could pop your manifold off, or at least bust the gaskets. That can also cause some bad hesitation. It kinda feels like a plug is out when your exhaust is clogged. Check out Random Technology for hi flow cats. Thats all the info I have so far. Good luck.
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