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Cats and Codes

Wamp

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Morning Fam. Forgive my ignorance, got a few Header CEL questions. I have stock exhaust manifolds.

1) If you run catted headers, do you get a CEL?

2) Does running E85 affect exhaust fault codes? (I’m aware that E85 emissions are different… heard stories of E85 and off-road mid pipes passing a sniff test.
Can’t verify the validity of the legend, though)

3) What has your experience been with headers, catted or off-road? Anyone had tickets, pissed off neighbors, or other header issues?
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Jackson1320

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Catted headers will still have codes and you can not pass a full smog test because the car is not a flex fuel car so they will fail it for running e85 and for the tune. If they just do a plug in test then you have a chance
 

mangosmoothie

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1. High flow cats will likely throw a code. The electronic emissions tests are usually just looking for active fault codes and "not ready" codes. Some tuners play with the parameters that trigger the CEL. In that case you can likely get away with high flow cats and not throw a cel. Some tuners can just disable the code altogether, but it'll show up as "not ready". BUT some states DO allow you have up to 2 not ready codes though. So it really depends on where you're at and what they're looking for. High flow cats smell like catless too, seriously doubt they'd pass a sniff test

2. Getting a tune for E85 won't throw a code or alter the way the ECU checks if the cat is functioning. The emissions station would be none the wiser if they aren't sniffing it. Which, if they do, I'd assume you'd have a 91/93 tune you could run for a few hundred miles before going in (most ECU's make need to meet certain driving parameters in order to be "ready". when you switch tunes those all get re-set)

3. Even in quiet start mode my roommates think my car is loud on start up. Then my active exhaust failed with the valves stuck wide open. Once I was in the neighborhood I shut the car off and coasted home. Had to fire it up to pull up the driveway. In just that short time a neighbor approached me. "Can your car be any more obnoxious?" well it's broken right now, going to fix it before I regularly drive it again. "F***ing right you are, I'm reporting it" This is the same person that yelled at me for working on my truck in my garage at 930 pm on a Friday though lol.

These cars do get quite loud with headers. I'd say "normal mode" with headers and X pipe is as loud as "track mode" was when totally stock.
 
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fmc_smt

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These cars do get quite loud with headers. I'd say "normal mode" with headers and X pipe is as loud as "track mode" was when totally stock.
You should hear them with an off road pipe and no active exhaust .
 

Jackson1320

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1. High flow cats will likely throw a code. The electronic emissions tests are usually just looking for active fault codes and "not ready" codes. Some tuners play with the parameters that trigger the CEL. In that case you can likely get away with high flow cats and not throw a cel. Some tuners can just disable the code altogether, but it'll show up as "not ready". BUT some states DO allow you have up to 2 not ready codes though. So it really depends on where you're at and what they're looking for. High flow cats smell like catless too, seriously doubt they'd pass a sniff test

2. Getting a tune for E85 won't throw a code or alter the way the ECU checks if the cat is functioning. The emissions station would be none the wiser if they aren't sniffing it. Which, if they do, I'd assume you'd have a 91/93 tune you could run for a few hundred miles before going in (most ECU's make need to meet certain driving parameters in order to be "ready". when you switch tunes those all get re-set)

3. Even in quiet start mode my roommates think my car is loud on start up. Then my active exhaust failed with the valves stuck wide open. Once I was in the neighborhood I shut the car off and coasted home. Had to fire it up to pull up the driveway. In just that short time a neighbor approached me. "Can your car be any more obnoxious?" well it's broken right now, going to fix it before I regularly drive it again. "F***ing right you are, I'm reporting it" This is the same person that yelled at me for working on my truck in my garage at 930 pm on a Friday though lol.

These cars do get quite loud with headers. I'd say "normal mode" with headers and X pipe is as loud as "track mode" was when totally stock.
States are starting to check for any modification in the tune. Most states will be doing this soon. Any modification to the tune without a E.O number will be a automatic fail
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