biopepper

So basically I finished a 5vz 3.4 swap in my 91 and when I had the exhaust done they put in the wrong 02 sensors and I was having major issues after figuring it out after disconnecting em it seemed to run a whole lot better just off the MAF so I got the correct densos (I think). I hooked the upstream just to see if it works but I'm still throwing p1130 (air fuel sensor circuit range/performance), p0171 (system too lean, which could just be k&n), and p0141 (b/c I don't have downstream hooked up). I got headers I don't know if that matters.

Now there's a couple issues first the motors 02 sensor wiring harness was cut off but I found a 99 Tacoma harness finding out its not the same but I had a buddy go through the wiring diagrams and he thinks he got it spliced good. Is there anyway I can test this?
Also I got the motor from a junk yard they said it was a 99 4runner. I got 99 4 runner sensors cali because I got it in California but I'm not 100% sure I called toyota and a couple dealers and they said they can't look up the motors serial # they need vin. With the 02 connected it is sluggish loss of power and a little jerky when I disconnected it's a lot better but still not right. So I dunno been dealing with this for a month getting frustrated any help would be awesome.

vital22re

iTrader: (2)

on the passenger side of the block there should be a vin tag riveted on. Try that or run the part number for the ecu at the dealer.

biopepper

Awesome good idea thanks!

SacRunner

I'd use the ECU part number before the VIN off the block; as far as I know, the blocks didn't really change much from 95.5 to 04 (aside from the dip stick hole not being drilled out on the later ones), but the electronics changed from year to year and application to application. And on top of everything else, it's the ECU that's going to throw a code, so you may as well get a sensor that works with that specific ECU rather than the block and hope that it works.

vital22re

iTrader: (2)

A vin number goes a long way. That's assuming the electronics/ecu haven't been replaced before and are original to the vehicle it came from. Having both bits would be nice. But yes you want the parts to match the ecu.

biopepper

Ok so cross referenced the ecu part# came back 99 cali 4 runner so at least that's right. So I'm guessing it's gotta be in my buddies wiring of the 02 harness. I wonder if I should just buy the harness that is actually meant for it i'm sure it's expensive though.

I just read this http://www.toyota-4runner.org/3rd-ge...ipped-out.html and one guy mentions you can't splice the 02 because they work on resistance? I'll hook it up to a meter tomorrow and see what my readings are.

TheDurk

As stated above, the ECU is what matters in Cali. vs. 49-state. If you can get the part number of the ECU, it is easy to determine which it is--easier then going from the VIN, which only the dealer can do. Otherwise, it is virtually impossible to know as the only visible differences are the front sensor, the truckside front sensor plug, the cross-over pipe, front exhaust bracket, and the converters, none of which came with your engine, I suspect. If the cross-over is original, the Cali. downstream flange has two holes, while the 49-state has only one. The exhaust manifolds are also slightly different, but I can't tell from my diagrams what that difference is--other than the part number.

As to checking your splicing, I have the paper versions of the FSM and the EWD for the '99 4Runner (which is my truck), so I can send you the pin-outs of the sensor wires at the ECU, and any other wiring info you need, if the ECU is indeed from a '99 4Runner.

Honestly, I would not consider doing a swap WITHOUT knowing the part number of the ECU involved. Seems sort of basic. You would also want to know if it is off a manual or an auto, as that affects a lot of wiring.

If it is off an auto, I suspect your CEL will be forever ON, if you are even hooking that up. Did a '91 even have one?

biopepper

I would love those diagrams i pm'ed you my email. So I got the part number of the ecu and it matches what I thought it was 99 4runner cali manual. Basically all the wiring harness is there except someone cut the part where it goes down to your 02 sensors so I got a friend who's pretty good with wiring to splice in the Tacoma one i found at a junkyard. Did you read my last post of possibly not being able to splice the 02s? Also I just drilled a hole for the front 02 after the headers precat.

TheDurk

That's horsehooey, IMO. It's not ideal, but for years Denso has been selling universal O2 sensors that have to be spliced after the plug. It does mean you need to do a good job: solder together a good inch+ of length and use heat shrink tubes--no stinkin' butt connectors. It is concerning that Denso does NOT sell universal A/F sensors for the front. My belief is they are more sensitive on splices, and there are concerns about the percentage of people who don't do it right, hence not selling universals, but it is still doable. A truly good splice is invisible to the circuit at these current levels, AFAIK. The A/F's are totally different electrically than the O2's--A/F's have constant voltage maintained by the ECM and it is the current that varies. O2's are just a varying resistance like most sensors.

I have to scan from paper, so give me a little time, but diagrams are on the way. That is exactly my truck: '99 4Runner w/5VZ-FE Cali. emissions 5-speed, so I can take pics, too, if needed.

Was the Taco a Cali.? Because the A/F sensor plugs are different. Multiple splices are certainly undesirable so if you have to change the plug in front, I'd go back to the yard and get a new piece and splice only once.

vital22re

iTrader: (2)

I just hope you didn't get the shielding contacting the inner signal wire as it would ground the signal. Hooking up to the computer and actually looking at the readings of the sensors would tell you that.

TheDurk

Engine Control Wiring Diagram sent. 32MB of attachments; let me know if you don't get it.

biopepper

Ya I don't see it in my email. As for the wiring I'm not 100% sure that the tacos harness was ca but I got it at cali junk yard. As for the wires I haven't soldered them their just tired together. That's a good idea to check the shielding. I'll go through the diagrams tomorrow and double check everything then solder it up. I'll prolly just buy the tacos diagram as I don't think the service manual is still floating around. How would I hook up directly to the computer?

vital22re

iTrader: (2)

get a scanner that can read live data and connect it to the obd2 diagnostic port.

biopepper

Ok thanks I got a buddy with one I'll see if he can come over today

biopepper

Awesome man just got it!!!! Thanks!

TheDurk

Well, if the A/F sensor plugs into it you know it was Cali. Like vital22re said, the ECU will check your wiring for you. If it doesn't see a sensor it likes, it will set codes in a heartbeat that you can read with the scanner or code reader on the OBDII port and it will tell you if the issue is heater side or sensor side. Did you rig up a port? Because you really need it with the 5VZ-FE. I strongly suggest you get your own scanner, too. Make sure you have no exhaust leaks ahead of the A/F; even a small one will screw things up. How did you get a flange sensor into a hole in a pipe, anyway?

BTW, what state are you in? I assume you don't have to get this thing through any emissions inspections. CARB would go into cardiac arrest.

Finally, reading back--have you cleaned your MAF sensor? This could resolve your P0171 and your performance issue in one fell swoop. But things will never be right until the ECU is happy with the A/F sensor. Otherwise it stays in open-loop (start-up mode) and kind of guesses at the fuel trim, so it will never run right. Usually it will run rich, so I'm a little surprised at the P0171.

biopepper

I got the odb port I just got a bluetooth reader for it and use torque on my phone to grab the codes. If I reset the codes they don't come back right away takes some driving then it throws codes and starts running like crap. I do know I have a small exhaust leak on the right header where it connects to exhaust the frames in the way so it's a pita to get too I thought I tightened it pretty good but it still leaks a little. As for the flange o2 I just drilled a hole for it and two threaded holes for the bolts and used some exhaust sealer lol. As for MAF that was my first step cleaning it also its new when I finished building the swap.

I'm in ca but I've kept the truck on non op so I don't have to get it smogged and where I live they don't require yearly smogs so I'm not concerned with that. What's weird is that once it starts to try and run off the sensor it seems like it runs lean if I reset ecu and disconnect it runs much better but definitely rich.

As for the wiring I'm pretty bad at it lol hoping my buddy can come tomorrow but all the colors match up on both harnesses except the tacos pink/green is connected to the 4runners black wire. Also when I put the new denso flange I had to flip the tacos plug around to make it fit (not ca?) But the old ones the exhaust shop put on fit it but I don't even have any idea what they were.

biopepper

Also when I had the old o2s the exhaust shop put on it ran super super lean sometimes I would even lose all power barley being able to Rev.

TheDurk

Well, you may have to fix your exhaust leak. And just twisting the wires won't cut it in this application--that's for sure.

So I guess we wait until you hook her up and tell us if there are any codes and how she runs. Just for fun, mind telling us what brand and part number A/F sensor you put in? I hope it's Denso or Toyota.

biopepper

Yeah from what I can tell I'm pretty sure he got the wiring all set last time I might as well just solder em together and see what happens. I'm using denso 234-9003. I'm a go solder them and drive it around for a bit see if the codes pop back up I'll let ya know what happens thanks again.