So my problem which has been here for a year now, is narrowed down to an exhaust leak. I found that the exhaust is my most hated part on the car. No matter where i turn theres a leak. So my main leak is where the cat meets the manifold.

I have a 99 ex OEM exhaust mani, and a standard ebay highflow cat for like 20 bucks. Sometimes it seals, but most times it doesnt. Its REALLY bad, i cant accellerate for ****.

Im using a donut gasket that seems to fit pretty well, however the cat and manifold seems like they dont line up perfectly. this is the 5th manifold yet, and still doesnt line up, so im thinking

Do I need a softer donut gasket? something that will conform better? i pulled mine off today, and saw there is a "raise" in the peice of **** converter. Kinda like somebody droped a drop of weld there. So its a high point. Well if kinda messed up my donut gasket a bit.

Could my cat converter inlet, be too large? too small? im pretty sure its 2.5", so im not sure what the OEM spec is. I dont have 200 bucks to spend on a real replacement, so i was also thinking about the OBX high flows for 60 bucks on ebay...would this work? along with a new donut gasket?

or i was also thinking i should get new bolts and REALLY tighten the cat to the manifold

 

if the flange on the header outlet is flat and true, then its your cat conv. You could go to a muffler shop and have them weld on a better flange or one that may be straigher or truer than the one on the cat right now.

most of those ebay cats are just resonators, a straight pipe if you will.

 

I can teel you that the outelt from the manifold is only 2.25" so if your high flow cat is 2.5" your going to have a non stop leak... I would go to w muffler shop and have them take a look...Midas or anywhere will look for free then tell you what needs done to fix it.

 

sad story, they said 290 bucks to fix it, i dont know if its MN, but not lying and its the 8th place i have checked.

anybody know the OEM inlet size of the OEM cat converter? is it 2.25?

 

i assume my current cat is 2.5....so can i use a larger OEM donut gasket to fill that 2.5?

 

Unfortunately thats not the way it works...the 2.5" donut gasket fits on a 2.5" ehaust manifold...you may try putting a 2.5" donut gasket ontop of the 2.25" gasket and bolting it up that way but i dont think that will work. just hit up a midas or something its free and they will tell you what you need. a lot easier than trial and error.

 

i already did, they are horrible, just said i needed a flex pipe for 300 bucks.

Should i just get another ebay resonator for 30 bucks that has a 2.25 in inlet? thanks man ive been sweating this for a while.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by YoungKadafi &raquo;</TD></TR><TR><TD CLASS="quote">i already did, they are horrible, just said i needed a flex pipe for 300 bucks.

Should i just get another ebay resonator for 30 bucks that has a 2.25 in inlet? thanks man ive been sweating this for a while.</TD></TR></TABLE>

That would be your best bet...do you have an aftermarket exhaust? if so make sure the resonator has a 60mm outlet (or 2.5") if its stock then 2.25" all the way and you should be good.

 

ok cool, dam either a carsound cat, or ebay....

would a carsound make my exhaust alot quieter? thats kinda what im aiming for, but very low on cash right now

 

I personaly cant say...i know that my test pipe made my car louder at higher RPM's but not much change down low...but i would imagine a cat would quiet it down some compared to a test pipe or resonator.