Your 02 is a narrowband that cycles like what you see in your graph when in closed loop. It's always trying to target stoich. That is the STFT correcting. Your graph looks totally normal.

Your 02 isn't used at WOT at all. Your wideband isn't controlled by the ECU and is just telling you what your AFR is at all times.

 

That's the O2 sensor reading, though; shouldnt't it rise when the wideband rises, and vice versa? I could understand if I was graphing STFT, but it seems like 2/3 of the time it's reading the opposite, and the other 1/3 of the time it's doing ok.

Its worth mentioning that the rear O2 I pulled out last year rattles when you shake it, so I wouldn't be surprised if the front is done too.

 

No, it won't map 1:1 to a wideband. The wideband is reporting AFR, the narrowband is reporting voltage.

What is your current LTFT idle and cruise in your logs?

 

Honestly, I think you might be in way over your head, it might be a good idea to take the car to a knowledgeable shop.

 

Here's them graphed out. It's worth noting that it idles super rich most of the time.

I definitely am. The problem is that no one around here'll poke the car with a 10 foot pole. There's a shop north of my city that does tuning, but I don't think they do much hardware related stuff. At this point, I'm just trying to fix as many things as I can so that I can convince some poor guy to figure out my mess. Either way I'm running out of big things to fix, so we'll find out sooner than later.

 

Trims are within normal spec.

wideband going full rich at idle is not. Almost looks like you have an exhaust leak close to the wideband

 

It's possible, but everything past the O2 housing on the turbo has never been touched. The wideband seems accurate though; the car is just spitting black smoke at idle. The lean spikes are accurate too, I have to accelerate super slowly, or else the car loses all power.

My working theory was it was something with the O2. When I was adding more fuel, it got way less lean on acceleration, and I think that might be because the STFT couldn't take away as much gas as it is with the proper injector scaling. This problem started over a year ago, after I practically nuked the engine on a hail mary drive home, and by the end of it I had wrecked 3/4 injectors and blacked out all my plugs. So it seems totally likely that something in the exhaust system is screwed up.

*wideband went in after the incident, so at least the sensor should be ok?

EDIT: are the wideband and narrowband not kinda doing the same thing? From what I've read, sounds like they're both reading oxygen concentration, with the wideband measuring ~10-20 AFR units(?) with 1-5v, and the narrowband measuring 14-16 AFR with 1-2V (both running 1v per 2 AFR units). I've just been assuming they're more or less the same sensor w/ different range/resolution.

EDIT again: I talked to some people, and they all agree that the O2 might be screwed up. Trying to install that other rear O2 as the front one, but the rust is so bad on the O2 that my twelve point wrench is just stripping it. Guy who owned the car before me said he said drove it everyday on a salted Canadian winter highway for as long as he had it, so no huge surprise. Wrecked my hands under the car trying to pull it off today, might be looking at a new downpipe (if I can manage to saw off the old one lmao). I have a good feeling about this one.

 

Turns out that instead of being shoved into the engine for more power, all of the boost decided it was going to jet oil out of the turbo lines. Brought it to that shop, found out one of the oil lines was leaking out. Turns out my father (who was helping me) dinged the feed line and it was spewing all over (couldn't tell, you know how exhaust + fluid is). I ran all of my pressure tests at TDC, so no engine pressure involved. Valuable lesson learned waiting for dyno results in the next few days.

 

Alright, so looks like I'm more or less back where I started. The guy at the shop says my turbo needs to get replaced (again), and the poor running is from my wheel speed sensors not working. I think he said it was something about the car not knowing if it's idling or cruising. I've rewired power to the ASC but still no dice. To clarify, I'm getting DTCs for ASC and AWC on the ETACS (just ASC on ECM, sounds like that's normal), but nothing else.




So on CAN-C, it seems like ASC and AWC are dead, which makes everything except for the SAS (I don't know? I think it's working, no DTCs) and the ECM, which I'm reading DTCs from. I'd say it can't be a coincidence, but I don't know what I'm talking about anyway. Doesn't seem like the two are connected in any other way other than the CAN line, but that would stop the ECM from working I think.

The ABS pump should be the same one as out of the RS, and the AWC ECU is out of an Evo X. I don't have any reference on the RS version, so I'm just gonna assume the pinout is the same. I might have my old harness laying around, so I'll see if anything jumps out at me. I'll try to brush up on this CAN line stuff. I know I can buy that VCI driver online, but I don't really know if running the MUT-III CAN diag is going to tell me anything.

EDIT: Checked old harness; wire colors are different, pin placement is identical.

 

Short update. I've replaced the AWC and ABS, ABS works now, AWC does not. I'm going to recheck the AWC situation when I get some time. With the new pump, the car idles properly (only when at a stop, lol), and drives a little bit better. I have some new DTCs to go after with the ABS pump now, hopefully those will help me solve the issue. I'm still convinced there's some sort of vacuum leak, but it's -30c outside these nights, so no work any time soon.