uppipe cat
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Car Info: iono nemore
uppipe cat
Dont kno if this is the right section but here it goes anyway
I kno the cat in the uppipe is there for cold starts so my question is..
Is the uppipe cat useless once the car is warmed up? I have a oem jdm spec dp and it only has one cat, and I need to know if that plus the cat in the uppipe will be enough to pass smog here or even in europe. thanks for your help
I kno the cat in the uppipe is there for cold starts so my question is..
Is the uppipe cat useless once the car is warmed up? I have a oem jdm spec dp and it only has one cat, and I need to know if that plus the cat in the uppipe will be enough to pass smog here or even in europe. thanks for your help
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Car Info: 02 Impreza WRX sedan
The uppipe cat is there mainly to provide some emissions control during cold startup. The remaining two cats after the turbo take longer to come up to 'light-off' temperature because they are just plain further away from the exhaust ports. The uppipe cat doesn't exactly become useless but once the other two warm up they usually have no trouble passing smog in OBD-II California testing.
Retaining the uppipe cat and going to the JDM system sounds a little unorthodox - most folks opt to get rid of the uppipe cat for both slightly quicker spoolup and less chance of chewing up the turbo impeller blade with pieces of catalyst that break free over time. I think people are passing smog in CA with just one cat in or after the downpipe but they don't post about it. I can't really say if your JDM downpipe will allow you to pass or not. Do you know many miles are on it? You might want to hold onto your stock exhaust just to be on the safe side for future testing.
One thing is for sure - you have to make sure that cat is fully warmed up before the sniffer test. Sitting there idling may not guarantee that it will be fully functional during the test.
--
0==WW==0
"…axles of evil…" - george w. bush
Retaining the uppipe cat and going to the JDM system sounds a little unorthodox - most folks opt to get rid of the uppipe cat for both slightly quicker spoolup and less chance of chewing up the turbo impeller blade with pieces of catalyst that break free over time. I think people are passing smog in CA with just one cat in or after the downpipe but they don't post about it. I can't really say if your JDM downpipe will allow you to pass or not. Do you know many miles are on it? You might want to hold onto your stock exhaust just to be on the safe side for future testing.
One thing is for sure - you have to make sure that cat is fully warmed up before the sniffer test. Sitting there idling may not guarantee that it will be fully functional during the test.
--
0==WW==0
"…axles of evil…" - george w. bush
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Car Info: iono nemore
well i no longer have my stock exhuast system doh for me.
I have a jdm spec exhaust and i really don't want to part with it but i also need to pass smog at the same time. is it possible to take the usdm 3rd cat and weld it into the jdm spec oem dp?
I have a jdm spec exhaust and i really don't want to part with it but i also need to pass smog at the same time. is it possible to take the usdm 3rd cat and weld it into the jdm spec oem dp?
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iTrader: (7)
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Posts: 10,029
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Car Info: 02 Impreza WRX sedan
Origami posted by oct1285
is it possible to take the usdm 3rd cat and weld it into the jdm spec oem dp?
is it possible to take the usdm 3rd cat and weld it into the jdm spec oem dp?
--
0==WW==0
"…axles of evil…" - george w. bush
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