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Q: My catalytic converters need to be replaced

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Ok, so my cats are bad. Would it be better to have an X pipe installed or just replace the cats? I'm military, therfore my truck is registered in Iowa. So I don't have to follow California regulations for smog or any of that stuff.

My car has 124755 miles.
My car has an automatic transmission.

A: Hi there, thanks for writing in. First of ...

Hi there, thanks for writing in.

First of all, removing a catalytic converter is illegal in all 50 states. They are federal emissions items, and there is a very stiff fine for removing or tampering with them on a vehicle that will be operated on public roadways. Second, I understand that that because the truck is registered in Iowa, you don’t technically need to meet the California smog requirements, but you should certainly try to if possible. The environment is already in pretty rough shape, partially due to emissions from personal vehicles. The vehicle is also designed to operate properly with the catalytic converters. If you remove the cats completely, your car may not gain any power, and will set a check engine light due to the missing cats, which can put your truck in a reduced power limp mode. You would have to have a full custom exhaust built that is suited to optimize flow with no catalytic converter, then would have to have the engine control module retuned for a race only mode where the cat delete is built in. If you opted to do all this work, then your vehicle would be completely illegal for use on public roadways, and any shop that did the work could be subject to a stiff penalty as well. Third, if you ever try to sell the truck, it would need to be in one of the few states that has no emissions checks at all. Most states look for the presence of a catalytic converter, and without one the truck cannot be registered by the new buyer. So you would have to sell it back in Iowa.

My suggestion is to replace the cats with an OEM equivalent part or better, and if you want better sound or slightly better performance, opt for a nice cat back system for you truck. You can have a qualified professional, such as one from YourMechanic, come to your home or work and replace the catalytic converters for you.

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