Exhaust/CEL problem

[Vice2kind]

HELP!!.. im having problems with my Mazda 3.. i recently just installed a exaust.. and now i dont have enough backpreasure.. and my engine light keeps comming on... the dealer told me to put the original muffler back on ( f*ck that ).. lol.. any advice Mazdaneers?

 

[goldwing2000]

What kind of exhaust did you install? Brand, size of pipes, components, etc.

 

[mobomelter]

hmmm did you remove both cats too?