newman.2020

Hi everyone. I got my swap all done, 92 pickup 3.doh swapped for a 3.4 out of a 2000 taco, mostly. Went with the toyonlyswaps crossover to driver side, and kept her stock height. So I have about a 1/2" spacer in the hood hinge to clear the 3.4. It can probably go lower, but I need to re-route the throttle cable, that's the highest point under there right now... anyway, it looks a lot better than a hood scoop, imo.

Point is, the truck looks pretty stock. So I thought I'd roll into the smog check and just get the thing passed, as the engine light was off, and she sounds so very nice and all. It worked fine. Dude had no idea it was the wrong engine, and I didn't even have to go into bs mode about blahblah intake manifold this and whatever i was gonna say about the hood height. But now, the engine light is back because of an O2 code. I want the ECU to be happy, not sending signals around under there like it is. The light was off for like a week and maybe 600 miles, for the record. And there is now an O2 sensor behind, as well as in front of the cat.

So finally getting to my question- Given the very clean, stock looking nature of the swap and everything, can I get away with a OBD1 cat? Will it just burn out quicker but be ok for a couple years or what? Or do I really need to get the damnable 2 cat 5vzfe thing welded on?

And please, I don't need to hear about BAR law and what ref is a nice guy and all this and that. Just technically will the ECU ever be cool over a couple years at least with an OBD1 cat?

Thanks..

hamish_18

dude 1 cat should be fine. Can you tell us at least what code you are seeing? That would help us out in determining what the issue is. I don't even have a cat and I have no codes. So trust me in saying any cat will work, as long as you pass your tests or whatever. Obviously I don't have to worry about it up here. With the code we can suggest what you should do and go from there.

bigarms23

ask the ref to tell you what wrong and go from there thats what the one i went through did and he asked if he could fix it to pass but also your cat doesn't matter im still running my 3.0 cat with a 4.3 motor.

newman.2020

and no check engine light huh? alright.

anyone else in CA what cat you runnin on yer 3.4 swap??

NytWolf

I'm in Sacramento, have a 2000 3.4 in my 92 pickup. I went ahead and did the two cats thing, cause I plan to get it refereed. I'm currently finishing up my exhaust though.

As far as the cats go, the first one is considered a pre-cat and the second one the actual cat. Other than the part number, I can't tell the difference though. I have Magnaflow OBDII CA-certified cats. 44005 for the front, and 41005 for the rear.

sirhk100

You know what's crazy on my swap. I don't have ANY O2 sensor in the exhaust yet. I have the threaded bung to weld in and I have a new O2 sensor ready to thread in. It's not plugged in and the harness is just ziptied in there right now. No codes, no check engine light. Now the thing is, I've had the computer throw other codes for many other reasons during the swap and the check engine light comes on when that happens. How mine is running bitchin and code free without any O2 in the system is beyond me! Mines from a '95 T100 donor...

newman.2020

that's amazing. i think my harness is hooked up too well. ha

still on the fence about it though... leaning toward new OBD1 cat though, see what happens. Seems like there's no "right" answer on this one.

NytWolf

If you really must have an answer, most people believe the OBD I cats work better than the newer OBD II cats.

cjsgarage

did you put a cat on it yet? the obdII cats would truly be the best option. It wont burn through a 3.0 cat necessarily fast, but the 3.0 cat isn't designed for what the 3.4 is putting out--whereas the 3.4 cat is.

Miller Catalyst in hayward is where I get mine. I own a shop in Livermore, CA, not too far from Oakland.

besides, in CA, all cats have to be certified now. an OBD1 cat will be just as expensive.

newman.2020

no way, the OBDII setup is more than twice as expensive. I put in the OBDI cat and everything's good. So if the rear O2 sensor is good with the emissions it is sensing... I see no problem. Especially since I'm doing the "under the radar" swap. I ouhgt to post up some pics of these details. Truck just looks regular, no scrappy hood scoop or nonsense like that.

On a side note, I rerouted the throttle cable so that it doesn't stick up higher than the forward driver side of the manifold. So I am now down to 1/4" spacers on each of the hood hinge bolts. old skate bearings work so well.

Hope this info helps somebody as I've taken tons of clues and ideas from YOTATECH.

yeeeee