Will no cat converter hurt motor

I was just wondering before I spend $ if driving without cat would hurt the engine by running too lean or rich. Previous owner removed it and check engine light stays on, po141, po441.

 

yes the motor needs back-pressure.

 

well, considering that ive seen guys drive just fine with nothing but header on the V6, i think you'd be fine, but emissions will fine you into the middle of next week.....

Edit: im not talking long distance everyday, but down the street to your exhaust shop is fine

 

I don't think it would hurt the motor, but probably hurt fuel economy, installing a urd o2 sim would probably help all around. No p0420 code?

 

Nope. Just hurts the environment

 

What all these guys up top said ^^^^ don't hurt the environment! Lol, just kidding, whatever...

 

OP, NO, assuming that your engine is a 2rz

I removed mine over a year ago, at the same time I had a Magnaflow muffler installed

The money that I spent on the URD sensor simulator and Magnaflow was well worth it, it has more than paid for itself in gas and it sounds much better

I used to get 22 mpg back and forth to work, for the last year I have been getting a steady 25 to 28, it just depends if I keep my foot out of it, for the most part I keep my foot out of it and get 27 to 28, Hwy I get 30 to 31

I have not had it on a Dyno but it picked up a little

As far as the environment goes, My Taco refuses to go green, it thinks scientists have lied to us

Here is the URD sensor simulator link
http://urdusa.com/Electronics-Rear-...,-2RZ-FE-2.4L-,-3RZ-FE-2.7L/product_info.html

I had to send mine back for them to tweak it, but it was worth it, check engine light has been off since then

 

Thanks very much for the urd link, and advice. The 97 Taco runs great with rebuilt 2.7, and a turbo muffler.

 

Wtf, back pressure is almost irrelevant on a EFI engine. You can run catless, you'll just throw a code and the engine will try to correct itself, giving a bad fuel mix.

Buy a cat, or get an O2 sim.

 

Not to forget.... It's illegal to run without it.

 

1. Back pressure is an old myth. Engines don't need it, period.
2. The ECU has enough authority to change the a/f ratio enough to compensate for any modifications you do to your air intake or exhaust by interpreting information sent to it from the primary o2 sensor. (In other words, the ECU can change the amount of fuel delivered to the engine by about +or- 15% depending on what the primary o2 sensor is telling it)
3. The secondary o2 sensor is not used for a/f ratio adjustments. It simply tells your ECU if your catalytic converter is operating correctly or not.

To answer your question though, it will not harm the engine and you can either get an o2 simulator to remove the codes from being generated, reinstall a cat, or live with it the way it is.

I don't have any emissions testing that I have to deal with where I live so I will probably remove my cat after the warranty runs out in an attempt to increase my fuel mileage a bit but I don't expect it to help much.

 

Dont expect to pass inspection without one