My cat is rattling and needs replacing.

Two questions:

1) Is there longevity/performance issues with the magnaflow cats? It seems people with the California versions have issues. Is this the case with the 49-state (non-ca) ones?

2) I just replaced my rear 02 sensor...is the bad cat damaging the new sensor?


Thanks.

vehicle is 2004 tacoma 3.4 liter

 

1.) I don't know because I'm required by law to buy only 50-state replacement cats, regardless of brand.

2.) I highly doubt it.

 

I have the 50 state one on my truck (was failing SMOG last year) and it's been fine. I've heard the "high flow" cats don't last as long, regardless of 49 or 50 state legality. I don't put that many miles on my truck so I don't care, and I didn't have a lot of choice anyway....

The 49 state cats are cheaper....I'd go with that since you're not in CA!

 

The high flow cats don't last as long but they are so much cheaper it usually works out better to just replace it every few years.

In my case I just built an O2 simulator and removed the Cat altogether, CEL stays off and since there is no tailpipe sniffer for OBDII cars I pass emissions no problem.

 

Hey TA - how do you build an O2 simulator? I just took a hit to my stock Cat while wheeling and need to replace it. However we don't have DEQ to pass here so if I can just knock it out that is fine by me.
With a 2.2" pulley and meth what do you think this might do to my HP and Torque curves? I tow, so I like to keep the torque decent a lower RPM's.
(I will have to PM you sometime about the 2.0" pulley you run. I didn't even know they made them that small, or how you mapped it?? )

 

There is a thread on here I followed. It used this diagram, the key point to make is you MUST leave the stock O2 sensor in place and working, the simulator simply TAPS into the wires to adjust the signal so the ECU thinks the cat is still in place. If you try to remove the O2 sensor it will not work.

Been running this way for about 4 years now with no issues, got a hobby box from radio shack, sealed it with silicone and it is ziptied under the truck. Think total cost was $15 or so.

http://www.vfaq.com/mods/O2bypass.html

The 2.0 pulley was honestly not worth it, just go with a 2.1" pulley if you want to max out the supercharger. Smaller then that and belt slip becomes almost impossible to deal with, plus you don't gain much power.

Thats why I pulled the supercharger off, maxed it out and it was still just way too slow for me. Gonna go turbo at some point and make some real power.

 

Any noticeable gains from knocking out the Cat?

 

A little, nothing to write home about. Saw someone that said it is around 8whp, which might be right. Just enough to feel but thats about it.

 

When my cats went bad I replaced them with one's I got from eBay similar to theses

http://www.ebay.com/itm/Toyota-4Runn...-/330461327066

http://www.ebay.com/itm/Toyota-4Runn...-/230511987434

Been running them for a while now with no issues, they even look close enough to factory that when I get smog tested they've always passed.