Is there a point to buy a High-Flow CAT?

You probably don't need to be that rich at wot, but that is more pretty conservative. It really won't gain you too much leaning it out to the high 10's to mid 11's.

I'm wondering if the ecu is pulling timing or how much timing did they pull from you. Did they give you a dyno sheet? If the motor pulls pretty happy to redline, but feels like a dog. Timing is most likely the issue. Toyota ECU's love pulling timing under boost.

If you can view maf voltage or read a flow rate from something you can pull the rear cats and see if that increases flow.

 

Hey Guys, I know this is an older thread, but I was wondering if I could get some advice, and this seemed like a good thread to ask my question.

I have a supercharger on my 4.0 installed by Toyota, with JBA shorty headers. Bought the truck recently, and it had an exhaust leak at the header-to-head interface. Drove it several thousand miles this way (2-3k maybe) and just before I got in my new header gaskets to fix the exhaust leak, I hear a rattle IN the exhaust pipe between the cats. I'm thinking maybe I have burned out a cat. I'm wondering what cat you all would recommend to replace the factory one welded to my shorty header if it is burned out?

TIA,
Coe

 

On my old truck, not a tacoma the heat shield on the cat kept coming lose causing a rattle.

Do you smell any exhaust near the cats while idling? If not it may just be a lose shield and a muffler shop should be able to fix at least temporarily.

Worth a shot.

 

Thanks for the ideas!

But since my earlier post, I had pulled my header and cat off, and it was indeed a cat burned up making the rattle. I replaced the cat/header assm with URD long-tube headers. A bit costly, but very worth it. A very seat-of-the-pants-noticeable mod. And not too bad to put on either. At least not with the ProComp 6" lift.

Final thoughts? If you hear a rattle near the cats, and it's not your heat shields, it's probably your cat.