# CEL trouble codes **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** gt, ford\ **Created:** [June 10, 2018, 7:49am UTC](https://community.cartalk.com/t/cel-trouble-codes/118980 "2018-06-10T07:49:39Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Sark5.0](https://avatars.discourse-cdn.com/v4/letter/s/8491ac/32.png) [@Sark5.0](https://community.cartalk.com/u/Sark5.0)\ **Post date:** [June 10, 2018, 7:49am UTC](https://community.cartalk.com/t/cel-trouble-codes/118980/1 "2018-06-10T07:49:39Z")
2016 mustang GT with muffler delete, magnaflow true x resonator and cat delete. CEL recently came on and is reading codes P0100, P0108 and P0110. I’m thinking it might have something to do with my cats getting removed about a month ago, but this is the first it’s started causing decrease in MPG and making my car run sluggish. Ford dealership said 4500 to return whole exhaust to stick to fix, no. Any cheaper suggestions for possible solutions? Would a tune or new intake fix? ---
**Author:** ![COROLLAGUY1](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/corollaguy1/32/7575_2.png) [@COROLLAGUY1](https://community.cartalk.com/u/COROLLAGUY1)\ **Post date:** [June 10, 2018, 10:36am UTC](https://community.cartalk.com/t/cel-trouble-codes/118980/2 "2018-06-10T10:36:48Z")
Computer has to be reprogrammed for this type of modification or it won’t read correctly.Take your car to a professional tuner for this. You can use a sparkplug defouler if you’re concerned about keeping the O2 sensor outside of the exhaust. Pulls the sensor out of the exhaust flow just enough to trick the sensor into thinking the cat’s present (or working). Also a great trick when your cat goes bad and you don’t want to buy a new one quite yet, or just want to sell the car.Removing a cat is illegal in most states and you could be fine $10,000 if you get caught. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [June 10, 2018, 12:40pm UTC](https://community.cartalk.com/t/cel-trouble-codes/118980/3 "2018-06-10T12:40:32Z")
> [@Sark5.0](#): > > my cats getting removed about a month ago, You know this is a federal crime, right? For both you and the shop that removed the cats. And it will never pass an emissions inspection if your state has one. They probably had you sign something that says you will only use the car off-road now that the cats are gone to protect the shop. You, on the other hand, are hanging out to dry. Up to $10,000 dry… see article > **[Catalytic Converter Laws](https://legalbeagle.com/7194804-catalytic-converter-laws.html)** > > The average automobile was a toxic chemical factory before catalytic converters were government-mandated in 1972. You can't touch catalytic converters unless you're replacing them like-for-like. Tampering with your cat is a criminal offense, save... There are catted X or H pipes sold WITH high flow aftermarket cats that will pass inspection in most states, not California and others. Usually run about $700 or so plus install. Since WE all breathe the same air as YOU do, put cats back on. You will never feel the slight power difference, if any.