i need some help..what would cause my engine to burn rich
ive change the ect sensor already.some one told me that the cold start injector could be bad,i heard the o2 sensor
my tail pipes are black as you can get.

 

thread moved and title made more specific

sounds like it certainly could be an O2 sensor. is the check engine light on? if so, have you checked to see what code is throwing the light on?

but at the same rate, a bad O2 sensor wont always throw the light on either; it didn't when the O2 sensor went bad in my 91

 

If your truck has the original 02 sensor with a lot of miles on it, replace it. Buy an OEM Denso replacement, Bosch 02 sensors don`t work well in toyota engines.