Alright, just picked up the truck, here's the deal. It runs absolutely amazing, but, two years ago it was labeled a gross polluter, now I am trying to get her smog legal. One of the things I noticed is that the O2 sensor has no wire coming out of it, and the trucks harness end is nowhere to be found. There isn't even a clipped wire poking out of the harness. This is where I get lost, I can not for the life of me find a diagram for it, let alone a couple pic's to have a visual reference. If anyone has an easily read-able digram or a picture that would be amazing. I'm also thinking of replacing the cat, maybe even the egr depending on how bad it is when I pull it tomorrow.

 

79 with an o2 sensor? Might be loosing my mind but you sure that isn't a typo?

unless you swapped to EFI anyways.

 

Pic of your "O2" sensor?..I don't think you have one
My 81 has a temp sensor on the cat..

 

Theres one there, unless the exhaust manifold is off a newer truck. Its in the same spot as my old 84's was. I wonder if the manifolds are the same between those trucks...

 

Here ya go.

 

Went to the four parts houses here this morning, no one can get or even has a picture of the manifold for 79. Everyone does list an o2 sensor. Went and looked at a buddys 1980, has an o2 sensor on it, its connected, but mine doesnt even have the harness end. Nothing. Im stuck now. Do the 79 and earlier even have a cel, cause nothing lights on the dash other than brake and charge.

 

looked at the dash very close, no cel on there. The plot thickens. What gets me is that the truck runs soooooo good its just unexplicable as to why she wont smog. Im thinking or replacing the cat and re-testing just to see if she passes. This truck is by far the best yota I have ever owned, the t-case gears coupled with 4.56's is amazing, first gear, just come off the clutch and let her go, climbs anything without hesitation and no throttle, tires are brand newish, straight clean body ready for primer and paint, the only rust is exhaust and a few small engine parts, body has zero. Maybe I should start gathering parts for an RE swap.

 

So, new parts: Cap, rotor, air filter, fuel filter, plugs and wires. Going to change the oil Thursday night, attempt to smog on friday after work, at least that way I can get some numbers as to what exactly is causing the fail. As per the O2 sensor, thats going to cause a visual fail. Can someone who has a stock engine in a 79 please put up a pic of their exhaust manifold?

 

You should just give it to me, stop wasting your time.
My '83 had an O2 sensor and a temp sensor in the cat, but even when I drove it around here with both unhooked/blocked off for awhile, no CEL ever came on or anything. Look in the driver side kick panel, near the fuse box. I remember there was supposed to be a control box or emissions relay or some sort of thing there that my '83 was missing, maybe yours is too and that's why no CEL?

After you get it smogged, put that Weber on, get a sync-link kit, a jet kit, and get out of my way, I'll have it running so good you'll think I put your Tundra motor in it!

Just don't look under the hood of the Tundra after that...

 

I was waiting for you to chime in. Haha. Idk, I just for three moving permits spanning about 2 weeks in 2010, all labeled for emisions/inspection. Not looking good.

 

By the driver kick panel? Try under steering column filled with glass fuses, lol, this things old.

 

I propose a fix, send it to me. Here in FL we don't have to SMOG vehicles. Which is a shame considering I think my 85 would pass.

 

Trade? Lol.

 

You read my mind, just ship yours over here first... then I will *cough* forget *cough* to send mine to you

 

The 1979 toyota trucks did not come with and O2 sensor. The Federal emissions trucks didn't even come with a catalytic converter, California emissions however did. It is likely that the O2 sensor manifold is either from a car or a different year of truck. 1982 was the first year for the O2 sensor in the manifold. Any 79-83 Toyota truck that has a catalytic converter will have a heat sensor in the cat (not an O2 sensor) Do you have the emissions sticker under your hood? Does it say "non catalysis"? If you contact me privately with your VIN # I can do some checking for you and tell you what you are supposed to have on your truck. I also have factory service manuals for the 79 and can scan pictures to post here.

 

Awesome. Ill pm you after work.

 

Heres an update, its been non op'ed since 2001, so only 164 in fees. But, it hasnt passed a smog check since its last one in 1996.

 

Also, according to the smog shop owner, it does not require an O2 sensor, he said if there is one in it, but not connected, it will be considered a required exhaust seal.

 

So"required exhaust seal" = a block off plate?

 

Any way to find out why it didn't pass? like which emission chemical was too high?