Ok I have 2 questions

[kneedragger25]

Hello all I am new to this forum and have asked a few Q's but you will get to know me pretty quick. Before I start I a lil about me I'm a mechanic by profession I work at Pepboys in Inglewood Ca and have an 04 Ex 4. V-6.
Question one what is the biggest tire I can use on the stock rim I would like a 32 or 31. once I get a Rb lift I will try 33's. I would like to keep the stock rims.
question 2 my 04 has three cats two pre and one main, I already have a flowmaster can and dual out and its sound decent but if I remove the main cat will I make the car run worse or will it not make a difference, also will it remove some back pressure or are the two pre cats the most restrictive? and yes I have searched but I cant seem to make it work right yet.

 

[BrianDye]

From what I recall, alot of the 3rd gen owners take theyre 3rd one off, or at least say theyre gonna lol

 

[Rofocowboy84]

There's been some debate, but it seems that the third "cat" is actually just a resonator. I'm not sure about the V6, but usually helping the exhaust flow better, up to a point at least, helps the car run better, not worse.

 

[Limited02]

I took mine off and I feel it runs better on top. Will it get sideways in every gear and beat Veyrons for lunch? No (sure would be nice though)

 

[05kAwBoy700]

Is there a possibility of loosing torque by removing the 3rd cat/resonator?

 

[macknos94]

it felt like i lost a little torque but wasn't bad. really nothing to worry about then again i took it off when i put on my flowmaster so that is probably what caused the torque loss

 

[Layinhp]

you wont actually "lose" power it just moves it around the torque band

 

[kneedragger25]

SO off comes my resocat thing Im sure its a cat based on the 02 sensor after it. My 92 t-bird SC had a resonator but no 02 after so this must be a cat. I'm in California so what about smog? will the front two be enough for me to still pass?

 

[CALDWELL]

I know CALI is strict on emissions etc...

my X did not have an 02 sensor after the ( 3rd cat / resonator ) so i just dropped it...

TQ is not lost completely, but more so moved around as said above me... what is dropped a lil bit in the LOW END, is greatly gained in the TOP END.

by loosing the ( 3rd Cat / Resonator ) will only really make the sound change and just free up the exhaust flow just a little bit more...

your post is a little bit confusing to read, but if i read it right, you say you have a CAT-BACK DUAL EXHAUST on a V6 ?

 

[Rofocowboy84]

SO off comes my resocat thing Im sure its a cat based on the 02 sensor after it. My 92 t-bird SC had a resonator but no 02 after so this must be a cat. I'm in California so what about smog? will the front two be enough for me to still pass?

Are you sure there's an O2 sensor after it? I saw the O2 sensors after the first two cats, but not the thing after the Y....

 

[xplorerguru]

Are you sure there's an O2 sensor after it? I saw the O2 sensors after the first two cats, but not the thing after the Y....

Hmmm, does anyone not have a third cat???? cause i dont, i have two than a long pipe after the y split......

 

[Limited02]

You are saying that when the Y meets, there isn't a large oval shaped "resonator" then it necks down to the 2.25" exhaust, then to the muffler and then out?

 

[kneedragger25]

What I did was remove the stock can and add a flowmaster then where the spare tire is I spliced in and added a second outlet pipe. and yes I have thre 02 sensors one after each cat then another after the main cat.