Not your average p0157. Please help.

That truck has been around the block! Props to the op for sorting it out. Long live salvage tacos!

 

Dm93 is the man!

 

It definitely has character. But this is what I signed up for haha. Definitely wouldn't be getting anywhere without the help!

 

Just throwing my $0.02 in without reading the entire thread. I’ve gotten p0157 codes with bad ignition coils on other vehicles even though the scanner and data points towards the o2 sensor.

 

Went around and did some hard pulls, with the wires shielded and everything. Based on what you said yesterday, it's looking like bank 2 cat is bad. Accel and decel matched up with what you pointed out.

Accel wot




Decel



I cleared the codes and let it idle in the driveway for a bit before taking off, had even thrown the old afr back in for shits and giggles to see if there was any possibility of a dud. But it's still got the same wonky fluctuations, and p0430 popped up again. On a good note though, that parking switch wire has seemingly cleared up the code about the transmission position.

 

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Looks pretty good aside from the marginal cat.
If you could sneak it past a visual inspection that cat may be marginal enough that an O2 spacer might keep the P0430 off long enough to pass.
I did a data capture on mine on the way to work this morning, I'll go through it and post some screenshots later tonight.

 

I looked over the exhaust again seeing if there was a leak manifold side or anything, the cat rattles pretty bad when I bang on it. I'm sure it's super toast. I don't think it'd pass visual unfortunately, you get under the truck and the O2 bung is staring at you dead in the face lol. Looking at it more and looking up replacements, they mangled the exhaust too. The manifolds/cats are welded directly to the y pipe/cats, so I can't even properly pull out 1 side without dropping the transmission brace, and taking both manifolds/y pipe out in one piece -_- That or cut it out in pieces. Looks like they just tossed in some shitty universal cats for the upstreams. I'm going to look at some 4runner cats and y pipe tomorrow since the Tacoma's are scarce rn, in theory those should fit since it's still a 4.0 right? Well the manifolds at least. Y pipe if it doesn't fit cause 4wd, I can always just repurpose the flanges and tack em on. I think lol.


Also ordered a new clock spring to see if that gets rid of the d squib airbag/angle codes codes. PO mentioned something about replacing the steering wheel, so they probably damaged it on install. Idk if those would throw off abs traction at all or not, but hopefully it fixes something.

 

Yea if it's rattling its done, when they come apart like that they tend to send all the crap downstream and plug up the downstream cat too.

I hate when people do that, there's no reason to.

Not sure but if you can weld It probably could be done, just do note there are 2 different designs (with secondary air ports and without) and they don't interchange. Yours will be without unless they put a 2012+ engine in it.

It might, I wonder if it blew the airbags when it was wrecked.

 

Here's some screenshots from my drive:

Cold start:
The upstreams are super lean on initial start because the secondary air pump is running, once it stops they go rich
As you can see it delays turning on the downstream heaters for quite awhile.



Decel & Hard Accel:
You can see they all go full lean on a decel and rich on accel, notice upstream voltage is inverse of downstream.



Cruise on a hilly road:
I scaled up the upstream sensors so you can see how much they oscillate compared to downstreams with good converters.

 

I honestly didn't even realize those were downstream cats since there's no sensors behind them to detect anything. Always thought they were resonators on my 4runner lol.

I'm pretty sure mine is without, I don't hear that hissing sound on start up like my buddy's 12, as I don't see any other ports on my exhaust than the sensor bungs. The 4runner I'm pulling from is an 05, so I'm hoping for the most part it's a direct match. I know a lot of the front end is interchangeable, but to what extent I'm not sure. If the manifolds fit that's all I really care about at this point. I can make the other stuff mate up. I hope lol.

I was thinking the same, idk why else PO would replace the steering wheel. But to that extent would have replaced the dash too I'd imagine, since there's no visual signs of deployment anywhere. With the amount of damage the bumper support flanges and rad support have, I'd find it hard to believe that they didn't deploy. I mean nothing is caved in that I can tell, but there's stress fractures and warping all over the core support.

 

Ahhhh, yea I see what you mean. On accel it looks pretty much like a mirrored image on yours.

Damn I had no idea they oscillated that much, on mine they look fairly steady compared to the downstreams. I wonder if I can upscale my data streams to get a more accurate line. I'll have to check tomorrow. Hoping after I get these cats my charts look like yours lmao.

 

Yea they aren't monitored but they are there.

I know the truck isn't equipped with it but sometimes people mix and match engines. Tacoma V6s didn't have Secondary Air Injection added until 2012.

Yea it just doesn't look like it because they are wideband sensors, they can detect air/fuel ratios from around 12:1 to 18:1 whereas a standard O2 sensor can essentially only detect about 14.6:1 to 14.8:1 air/fuel ratios so it's voltage is much more sensitive to AFR changes.
AFR sensors don't really operate off voltage, they operate off micro-amps of current. Toyota just converts this to a voltage value to make it easier to decipher.
An O2 sensor makes it's own voltage but it can't accurately measure air fuel mixtures very well so they are mainly just used for catalyst monitoring on modern vehicles.

 

For anyone wondering, 4runner 4.0 manifolds fit the Tacoma perfectly. 2005-2005 at least. Y Pipe is a different story, will update if I gotta cut and weld.

 

Little update. This has been a frustrating adventure.

Firstly, the manifolds do mate up to the engine just fine. But either my welds are crooked which is entirely possible, cause I'm still new to it(2wd 4runner mid pipe does not fit), or they're just slightly angled differently enough to make fitment an issue with the rest of the exhaust. I got everything bolted up, the muffler pipe makes contact with the frame just past where it meets the midpipe. Not the worst. Ran the data stream, bank 2 is looking phenomenal. Bank 1, now having an erratic graph like bank 2 was. Drive cycle completed and it was not throwing any codes, which was surprising. But I was happy. Today not so much, ended up throwing p420, on the way to the smog shop. I'm thinking I bought a bad cat, since it was off a wrecker. Went down and checked fitment again before I cut the one good cat in, and found that the midpipe/muffler flange was pumping out a lot of air. Adjusted the midpipe, then the secondary cat flanges started dumping air. Messed around enough to where I couldn't feel air coming out of anywhere, but it's janky as hell. Got bank 1 looking good again, now bank 2 is a little erratic again. But it's looking better than it was initially. If it's good enough, but hoping. Waiting for the evap monitor to clear hopefully rush and get to the smog shop when the scanner gives me an emissions ready message.



As for literally all the other codes, the abs and stuff goes away so long as I'm not throwing the theres no emissions code. And the airbag stuff went away with replacing the clock spring. These dummies installed a clock spring, and instead of pulling the safety tab out, they just snapped it off -_-. I'm starting to have reservations about how well the engine swap went. Changed the oil and spark plugs, the oil was dark as hell, the oil filter gasket was fused to the mating surface, and the spark plugs were caked up in a chocolate sludge. Mostly by the threads, pretty sure that probably the valve cover orings right? Plug wells weren't wet though, little confused on that. There's green coolant in the engine block, and pink coolant in the reservoir, so a coolant flush and fill is next on the list after I get the smog situated.


Sounds much better with just that basic maintenance though. Valve tick is much quieter. Can't wait to see what else I find.

 

Glad it's working out for you, yea unfortunately hackjob work isn't all that uncommon. I get stuff in the shop all the time that is all rigged.

Evap monitor runs 5-10 hrs after shutdown (Coolant & Intake Air Temp must go below 95F) after at least a 5 min drive so that should run withing a couple days.

 

Oh perfect! I'm gonna run to get that smog first thing in the morning lmao.

Thanks again for all your help man, I really can't stress it enough how big of a help you were, don't think I could have gotten this far without your advice. I wouldn't recommend it, but if you ever find yourself in Cali, I definitely owe you some beers.

 

We did it boys! Passed emissions with flying colors!

 

Nice, thanks for coming back with a conclusion

 

This was definitely a test of will for sure. So glad it's over with, now I can focus on actually getting the damn truck to drive straight and ride right lmao.