I have a 99 ex with the d16y8 and I have recently gutted the cat and taken off the muffler for a cheap ricer sound...my car now backfires when I let off the gas and it is running rich and I dont know what to do to fix those problems...any help would be appreciated

 

obvious answer....put a working cat back on :slap:

 

well you just made a nice expensive fix for your car. without a properly working cat your car is going to act all sorts of fucked up. put a working cat back on the car and dont do something that stupid again.

with a gutted cat your o2 sensor will be reading way way way too many nox, carbon monoxide and hydro carbon particles exiting the cat. i'm surprised you arent throwing a code right now.

 

I had to gut the cat because at the time my cat was clogged and my car wasnt running and it was like $125 for a new cat

 

well now you more than likely will have to buy a new o2 sensor as well as a new cat and pay whatever it costs to get them installed if you cant do it yourself.

a properly working cat is essential to a well running vehicle in any vehicle with an emissions system.

and just an fyi, cats never commit suicide, something else wrong in the system always kills them, so if you had a bad cat you may want to do some investigating and find out why it died.

 

arent the cats covered under warranty for 8 years?
my friend has the same problem and failed emissions. but was noted of this warranty that the deals hafta go by..

 

it prolly was ... until he gutted it. at that point he's fucked

 

I planned on getting catback soon anyways...and its because Im running rich my cat clogged up...why would I be running rich??

 

One of the main reasons for running rich is a bad O2 sensor.

 

is there anyway to know which one??