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Discussion Starter · #1 ·
I never really looked under the car till today (so shoot me). Is the actually 2 mufflers? Or 2 cats and one muffler? That would explain why the car is so quiet!

Oh, and I think the stock pipe routing sucks
 

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RWD is teh bomb
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Actually.. I think its one cat, one muffler, and dual exhaust tips. Guys, correct me if I'm wrong?
 

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Discussion Starter · #3 ·
When I looked under (from the side of my car) I could see the heat shielding from what looked like that cat, then a muffler shaped object (cat or muffler?), then the pipes go back to the muffler w/ dual tips....

I could be wrong though, cause i havnt had the car up on a lift
 

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sr20reNaISSANce said:
there are two cats. exhaust manifold (cat inside), flex pipe, cat, resonator, one muffler, two tips
Ding Ding Ding you win:)
 

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Kevin C.---'01 SR20DE said:
Where are the O2 sensors? Is there one after the second cat? If not, i'm ditching it an keeping the first one.
keep the 2nd one because its the one that does most of the work. the first one is just basically for cleaner start ups. since its closer to the front, it heats up faster than just one in the traditional spot. to me, the first one is totally useless because without it, it makes no difference after 5 minutes or so. i guess nissan is putting us up against a honda civic dx....hahaha.
 

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oh crap...i was talking bout the cats. well as for the o2 sensor, dont ditch. heres how they work.
the 1st one is a base, before the 1st cat. it reads how dirty the exhaust is.
the 2nd one is after the 1st cat and before the 2nd cat. it supposed to read cleaner than the first one.
so without the 1st 1st cat, the sensors will read the same, which is bad. then the car senses that there is a problem, so it runs in a "safe mode" which means it runs rich, to ensure safety. so removing the/a sensor will just give you the light. just have to wait for an ecu or maybe relocate your 2nd o2 sensor behind your 2nd cat.
 

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Discussion Starter · #14 ·
So if you put on the hotshot header you will have to move the O2 sensors, right?

I know some people with other cars that used a certain resistor spliced into the wiring on the downstream O2 sensor to fake out the pcm thinking that everything was operating fine, even when the sensor wasnt even in the pipe :)

I'll be able to work something out
 
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