Tacoma running rich no CEL

Help!

My 2011 Tacoma 4.0 is running really rich. I've replaced the spark plugs, verified that there aren't any leaks in my exhaust (headers all the way to tip), tried switching back to stock intake, removed my UNICHIP and cleaned my MAF sensor. Im running out of solutions. my next guess would be O2 sensors maybe but it's so strange that I'm not throwing a code. Any help would be awesome.

 

What did your plugs look like?

 

Is it still blowing black smoke as you posted with the Unichip?

https://www.tacomaworld.com/threads/2011-tacoma-running-rich-with-unichip.458526/

Did you reset the ECU by disconnecting the battery?

Are you sure those readings are correct with the Unichip out as they look to be the same as with the chip?

 

Possible causes of a rich mixture

- Dirty air filter

- Stuck open injectors

- Bad oxygen sensors

- Faulty ECU

- Bad Mass Airflow sensor

- Retrofitted cooling system (Thermostat removed, Fan running direct, double cell radiator)

- Bad Engine Coolant Temperature (ECT) Sensor

 

I will include a picture of the plugs they all looked about the same, som were more black than others. it is still blowing smoke at high RPMs and I did disconnect the battery while I was replacing the plugs. And sorry, that was the same screen shot I will also include an updated one of after I removed the unichip. I am now peaking at 10 sometimes but other than that, there isn't much change in the ratio. Also, my gap max is .043 and the ones I took out ranged from .045-.056.

 

Something is up with the ecu or data being sent to it via varoius sensors... its running rich cus the ecu is telling it. AFR(c) = AFR commanded... or what the ecu wants the motor to run at. ARF(m) = ARF Measured ... or what the O2 sensors before the first cat are seeing.

The AFR(c) should be at 14.7:1 when cruising, sometimes dipping a lil to mid 13's depending on load, and WOT is around 11.5:1

 

So maybe the O2 sensors could be bad? Or should I like into getting the ECU reflashed?

 

Love that you are using Torque, no look at more information, O2 readings, LT+ST Fuel Trims, (Intake, Coolant, and CAT) temps.

 

Sarcasm? and anything in particular i should I be looking for?

 

Not sarcasm. It's just more info to help determine what's going on. I like this setup, post some screenshots so we know more.

 

Ok cool. I'll set it up like that and post some more pictures. thanks!

 

The first 2 pictures are at idle and the second 2 are at just over 40mph. All photos after engine had warmed up. thanks!

 

To me it looks like you need to focus on bank 1 (dunno which side that is right off). A long term fuel trim more than 10% +/- is going to throw a code. Looks like an idle issue based on the 40mph coming back up towards 0.

 

So I guess since it's not quite at that +/- 10% that's why it hasn't thrown a code yet?

 

Here's mine for comparison,idle.

 

Ok, I see some differences but I'm not sure what some of it means. Any help translating/thoughts would be helpful haha

 

already gave my opinions. Maybe others can chime in now that there is more information available.

 

I saw what you said but since I'm not completely savvy when it comes to the science of all of this, I'm a little out of my league haha since you've said it looks like bank 1/idle issue, what do you think the possible causes could be given those circumstances?

 

O2 sensors are supposed to have a Rise/Fall pattern like the ones in my screenshot. Check and see if yours are doing that. Also see if you can find the "Fuel Status" gauge, in the guage type list, so we can see if it's running closed loop/open loop.

 

Many 1GR's run in the 10:1 + or - AFR's, at WOT. That is actually normal. Even mine does. Being that the engine is in an Open Loop state while that rich AFR takes place, a code won't set. If it were in Closed Loop, it definitely would set, if it were out of tolerance for too long.

Tuning will get it to where it needs to be. Seeing that your UniChip didn't raise the AFR's into the 12's @ WOT, but made it more rich, then it needs to have the tune refined.

~10:8-11.5 for boost, and ~12-12.5 for N/A. On gasoline.