: cats wasted?

04-10-11, 04:02 PM
For a while I have been getting that sulfur smell after a mid to high rpm run. I am figuring that they are needing replaced since they are probably stock with 106k. It an 04 with a k&n and muffler delete. Everything else is stock.

Question is will high flow cats make that much of a difference? I know I will need a tune if I go that way, but is it worth itfor the cost or just get a couple used take offs?

I hate my car smelling like rotten eggs.

04-10-11, 04:31 PM
Whether high-flow cats are worth it depends on what you are trying to do.

Random Tech cats run $700+ a set and will get you 10-15 hp with a Wait4Me Tune that runs about $160 the last time I checked. The Wait4Me tune also gets you a spare ECM. You should also see about 2 mpg increase in fuel economy.

Mandrel Exhaust Systems has some high-flow cats for about $290 which should accomplish the same thing. The problem is that a tune is required to avoid check engine lights.

Finally. the the horsepower potential increases if you do additional mods (cam, heads, etc.).

04-10-11, 05:40 PM
Where can you get the mandrel exhaust system cats?

04-10-11, 05:52 PM
Google mandrel exhaust systems.

04-10-11, 11:53 PM

04-11-11, 08:49 AM

Read that thread...it has all the info and a couple reviews. I still like these cats but I continue to have trouble with the manifold to cat gaskets. They keep blowing out. The gaskets they supplied didn't last long and they weren't really the right size (inner diameter wasn't quite big enough and the stud wholes didn't line up). I took measurements and worked with them to get the right size gaskets. The replacements they sent were better but they didn't last long either (and still weren't the right size for the stud holes even though I sent them correct measurements). I sourced my own gaskets from autozone and put them in yesterday. I hope these last as they have the right size inner diameter and are thicker. Fingers crossed! If they last I'll post up the part number for others.

04-11-11, 01:37 PM
Thanks Houdini. Did you have any noticable difference with the cats and the W4M tune? Usually you won't "feel" 10 hp, but sometimes it feels like alot more, just curious.

04-11-11, 08:59 PM
The rich factory PE mode in these cars probably doesn't help matters. I have smelled mine at times, after a hard run. 103k.

04-11-11, 09:36 PM
take your exhaust off, bang the shit out of the cats with a prybar, pull all the goop and dust and chunks out of them, drive to the local dyno shop, or even regular shop for that matter, and get a full tune, including one that makes your check engine light shut up when you don't have a catalyst in place.

rambling saves you money.