4.0L Tacoma Running Very Rich

Is there anyone else out there that is experiencing an unusual amount of carbon build-up on the exhaust tip? I don't use "garbage" gasoline and take very good care of my vehicles also, I never experienced this with my 2004 Tacoma w/ the 3.4L engine. Please advise..........

 

Mine has done it since the begining. Look at all Tacomas you see and youll notice we are not alone.

 

Yeah, they do run a bit rich sometimes IMO. It might help to clean your throttle plates and run some injector cleaner if it gets bad.

Remember that even though the Tacoma is certified as a low emission vehicle, they don't test it under every condition. Like the conditions where being too lean would make them blow up.

AFAIK, they don't test them WFO, or under extended hard duty, pulling stumps, hopping rocks, or hauling the boat. They use a standardized driving cycle that represents the average suburban soccer mom on her daily trek to the mall and back.

What the truck does outside of that specific driving cycle is pretty much up to Toyota.

 

It's normal....

Nothing wrong with running rich. The engine runs cooler that way versus lean/hot.

 

Normal.

Just your exhaust is turning black? Hell, my whole quarter panel gets covered with soot.

 

Welcome to TW

 

run some techron thru the tank, and maybe clean the throttle body. other than that, ts pretty normal for the 4.0. you can also get a slip on/bolt over exhaust tip if the soot is getting on the fender at all. just a heads up.

by the way....welcome to tw!!