For all you guys who are running straight pipes to a muffler....

...there's a wire coming out of the cat. Is there anything else that needs to be "disabled" or "removed" so this wire no longer plays a role in anything??

Thanks, guys.

 

Is that wire for the o2 sensor? Where does that wire run to if its not the o2 sensor wire? All I have is one o2 for the engines purpose and one for wideband.

 

There's a wire in your cat?

I'm sure the 70's Toyota pickups didnt have O2 sensors......

interesting... I'm afraid to know what happened! lol

 

if your truck does not have an ecu it doesnt have an o2 sensor, don't know why you would have a wire on a cat anyways?!

 

It's a thick wire with a 3-inch sensor of some sort that was fitted into a small hole on the side of the cat, and bolted down with a clamp and a couple of screws.

I'll try and take some pics of it tomorrow.

Haven't had a chance to see where the other end of the wire leads to, but it did come down through a hole from the cab. For now, I just pushed whatever slack there was back into the cab.

It was obviously there for a reason, and since my cat was stolen (that's my story and I'm sticking to it ) I'm wondering what I need to do to disable the sensor.

Didn't want to just cut into it...

 

sounds like an o2...screw it, just cut it out

 

this is on a 70s truck?

 

Sounds like someone put a junk yard cat on it lol...

 

77' sr5

 

Come to think of it, you're prolly pretty close. Now that you mentioned it, I do recall the previous owner mentioning that he just had the cat replaced just before his last smog check. Had some muffler shop do it for $100+.

May have just pulled one off the shelf that went to a different car, just so it would pass smog.

Makes sense, now.

Just kinda threw me for a second since I'd never seen one on any of my other trucks, before.

 

Cat Temp Sensor

What you have is, I believe, a Cat Temp Sensor on your catalytic converter.

I had an 81 Starlet w/a 4KC and a 77 Corolla with a 3KC that had these sensors. There was a dummy light in the gauge cluster for Exhaust Overheat.

 

so the exhaust can melt?! lol

 

Well, I traced the wire (pic shortly) into the cab and found that it was connected to a harness of wires that ran across the spine of the hump and up behind the heater, into the firewall. So, whatever it is, it isn't just some dummy sensor that came with an off-the-shelf-cat.

Simply disconnected the sensor at the connection in the cab.

It started to rain (outdoor workshop) so I didn't get a chance to trace it from the firewall. But I will, even just out of curiosity, and see where it leads to.

 

What you have is a replacement converter. With a fitted thermosensor. It basically controls exhaust temperature and isn't a necessarily important part I don't think you will ever get hot enough to need it but I also am no professional so wtf do I know Lol.

 

its amazing how people with no experience think they know it all.




YES

that is a temp sensor.
and its stock, oem, from japan.

more typically found on cali emissions trucks.



its a super cheesy way for the emissions equipment to tell a rich or lean condition by the cat temp.



cut it off throw away, unless you still run the stock carb. then keep everything stock or it freaks out.

 

Need I say more?

I thought it odd for someone to go through all the trouble to put a "dummy" sensor that actually wired into the harness. Nothing about the wiring, from sensor to firewall, looked "backyard" done.

Thanks, man.

 

im not one to start nothing but i hope that wasnt a shot at me... i was just trying to help and as i stated im no professional its just what i read in my chilton toyota book.

 

someone really did steal the cat off my 03 frontier, and the sucker never ran better. I just put a straight pipe over it as the cat was 300 bucks.
It sounds better and I get better gas milage. I do have a check engine light on since, but it doesnt seem to have f#&$ it up too bad.
This was over a year ago.

 

Relax, man. That could have easily been a shot at ME.

We're in a public forum, with guys all across the nation. Some from different countries. Different backgrounds, different lifestyles, different approaches to everything - from wrenching to communicating.

Take NOTHING personal.

Inquire, read, and learn from what you can. Share what you know, to your heart's content. Most importantly, shrug off what you don't find beneficial to your ride and/or your pride.

It's all good.

 

dude, we're a ToyMini family