I have a maxima 2003 which have VQ30 and I'm thinking about deleting my catalytic converter to make it sound better, I already replaced the muffler with one that make sound, but it does not have much of fun, and I'm thinking does that ruin my fuel consumption? Even if I did tuned it? And is it that much or not? And if it might ruin something else in the car or not?

Let me know what do you think guys?

 

2003 came with the VQ35DE, are you sure you have an older engine VQ30 in your 2003? and if you want more noise just get another muffler. maybe a 3"

 

probably outside of NA. i think middle east got the vq30 in 02/03

 

ahh ok i didn't think of that, also that changes the cat layout too, but OP if you only care about noise. get a custom exhaust or larger muffler. deleting cats will change the tone but its not worth it if noise is what your after.

full custom exhaust if you have the bank to do it.

 

Leave the main cat, the car will smell bad without it.