VEDAVOO

I Have An 84 4runner Carb Not Efi And Was Considering Upgrading The Stock Exhuast. It Has An O2 Sensor In The Exhuast Manifold And What Appears To Be Some Sort Of Thermal Coupler Or Someype Of O2 Sensor In The Catalytic Conv Also.does Anyone Know What Exactly It Is. I Also Have And 84 Truck That Has No O2 Sensor Any Where On The Truck. There Is A Obvious Difference Between The Two Trucks But What Is It, Is What I Want To Know.

VEDAVOO

Would A Picture Help Someone Identify What I Am Talking About? I Am Guessing It Is Just An Early Obdii System Just Have Not Seen This System On An Carb Toyota. I Want To Upgrade And Need To Know If It Is A Secondary O2 Sensor Or Something Else It Does'nt Look The Same As The Front O2 Sensor.need To Know Before I Start Cutting And Remove Anything That Should Not Be Removed.

abecedarian

yeah, pics would absolutely help.
For what it's worth, OBDII systems started in late 94 and were the standard in 95.5.
You may have air injection to the cat. If it's got no wires, just a pipe going in, possibly what I said. Some toy's have an air pump that injects air into the exhaust.
As for the rest, if you're talking after the cat, 2 - 2.25" pipe into your favorite sounding muffler (flowmaster, magnaflow, ???... I prefer magnaflow) won't hurt you at all.

stagger_lee

What state do you live in? If its not CAli, cut it all out and do what you want. The air pump into the cat serves the purpose of warming the CAT faster in order for it to do its job of eliminating harmful exhaust into the atmosphere faster. A warm cat does a better job of that.

I'll check my 84 runner and see what I have under there and we can compare and come up with an answer. Its not an O2 sensor though I'll tell you that. lol. Cheers!

XtraSlow_XtraCab

I asked an older, very skilled exhaust builder down at the local muffler shop and he called it an "exhaust probe". I believe all it does is "keep record" of what kind of readings you have. You see, although the 22R is a carbed motor, you'll notice a computer device on the passenger side kick panel.

An oxygen sensor on an EFI engine actually helps the computer determine what mixture is best suited and is automatically programmed.

The "exhaust probe" for a carbureted motor merely monitors what's going on in the cat but does not do anything to help YOU the owner out (since carburetors are obviously adjusted manually).

I also noticed on MY 22R (Calif.) that there is a diagnostic plug-in of some sort near the ignition coil. Dunno what the heck it does since its not fuel injection to spit out error codes, but it must do something (probably for emissions specifically).

Now, I uh... happened to misplace my cat and it's exhaust probe (which somehow became unplugged near the floor pan) but the engine still runs tip-top. Hopefully I can find them by smog check season

FredTJ

So, you think that all of the other states, except for CA. is exempt from Federal law ??




Fred

stagger_lee

NO sir, but Cali is one of the handful of states that has the strict "sniff" test. I am not aware of blanket smog laws. I thought it was state to state. I will always run a cat because I'm not into polluting to maybe gain a few horses. Anyway, what are you, the fuzz?

VEDAVOO

I Live In Nebraska And Need To Replace All Of The Exhaust Its All Rusted Out. I Dont Want To Spend Much On It Now, Just Enough To Make It Through Winter. I Have A 2001 Tacoma 3.4l To Put In It Closer To Spring Time And Am Planing On Using Most Of The Exhaust Off The Tacoma.

VEDAVOO

Here Is A Couple Of Pictures. I Went Ahead And Cut The Flanges Off The Cat And Welded In Peice Of 2.5 Inch Pipe The Same Length As The Cat Into Its Place. Then Cut The Sensor Mount Off The Cat And Welded It At An Angle Into The Pipe. The Sensor Or Probe Is About 3.5 Inches Long Nothing I Have Ever Seen.then Used The Muffler Off The Tacoma I Am Parting Out Cut Pipe To Length And Welded The Flange On. Bolted It All Together And Good To Go Till Spring

XtraSlow_XtraCab

That my friend, is a test tube (not the laboratory kind). Its an old way of determining whether or not your catalytic converter is the specific reason a car doesn't pass smog. I also have one of those on my truck; regardless of horsepower gains if I only use my cat one month out of two years... I'll die of old age before it wears out

As far as becoming a "gross polluter" without a cat, that's simply absurd. Aside from the fact that older (more polluting) diesel rigs are not required to pass emissions, industry alone contributes to over half of the smog problems in California. I don't see my little 22R choking people to death while I 'm driving by, so its A-OK in my book

Overall, I'm not AGAINST emissions testing... my modifications are my business. However, the fact that the vehicle must pass a visual test on emissions equipment as well is strictly... retarded. If it runs clean, why fuss over anything else? I'm also disappointed that when debates on smog problems arise in the general population, the fingers always get pointed to old "classic" cars first. How can such a small amount of collector car owners be accused of smog for gasline/diesel vehicles of all years?

Yeah, that's my rant. I'm done.

VEDAVOO

The Way I Figure It, The Way I Have It Wont Hurt For A Few Months. Its Got To Be Better Than The Rust Holes In The Old Cat Venting Exhaust And The Noise Was Annoying.i Could Not Justify Replacing It. It Will Be Only 4 Or 5 Months Until I Swap In My 3.4l And I Plan On Putting In The Cat From The Tacoma And Aftermarket Stuff Behind That.

FredTJ

If you're talking about using the existing cat that came off of the Tacoma, then that's illegal also ....
Sometimes you just can't get a break




Fred

86Toyrunna

i just want to chime in and ask fredtj a question, why would using a cat off another truck Illegal? actually about to put my highflow cat of my old truck on my runner.

FredTJ

Because it's illegal to install a used cat on anything, and once a cat is installed in a vehicle it becomes "used".
By removing a cat and installing it on another vehicle, you're now installing a used cat.

I owned a tranny/auto repair shop for some years and one of our best friends has owned a shop for almost 30 years now.

I was a member of ATRA and they regularly sent out notices reminding all their members that once you drop an exhaust (as many do before removing a tranny), it is illegal to reuse the cat.

Though in that case the EPA seldom cared, the do, none the less, take action on this exact thing several times a year.





Fred

anotherjeff

"A good used Cat is as good as a new one!" (Except, those obd2 ones are something else!!!)

You get an attaboy for that nice job on the probe. I'm sure that would pass most state mandated inspections.

I believe that's a thermal probe. I even believe that my '78 Federal no-Cat PU has one (but's too late to go look...). Again, I believe, the exhaust temp was input to the primitive brain; which only had control of the Air Injection solenoid. And, it worked as a safeguard - if a threshold temp was reached, the Air Injection was defeated. I have a hunch that CA BAR doesn't even perceive it as Smog Related Equipment. (Any techs out there?)

XtraSlow_XtraCab

I would say they DO relate it to that. In both Chiltons and the FSM, my choke setup for the carburetor was listed under EMISSIONS sections and not under FUEL DELIVERY sections. I thought that was stupid. All because of the choke breaker.

stagger_lee

The cat does significantly reduce the amount of harmful gas emitted into the atmosphere. Obviously next to a V8 it will be less on our 22r, but its all relevant. I'm only worried about doing what I can to not pollute. I recycle and ride my bike a lot too. Call me a hippie. At the same time I want to stick it to the fascist totalitarianism man they call government, at all cost. Cut my pipes off and blow it right into their houses of authority. There's my rant.

In a sense I agree with you xtraslow!

jodaddy

I use that plug next to the coil to hook up my tach/dwell meter

abecedarian

actually, it's not a breaker that makes it emissions. it's the fact that there are cold engine emissions specifications involving HC emissions and the length of time it takes to transition from cold to warm operation.