2002 Caravan SE V6, 95k with increasingly black smoke, soot from tail pipe. Now has worsening hesitation, check engine light, and a P0171 code which reads "Fuel trim system lean bank 1". I was thinking oxygen sensors since the reading was lean.

Anything else I should be thinking of instead?

Thanks

 

U should really have some one with experence look at it unless u want to just throw parts and money at it. Lean code is to much fuel so the computer is taking away more then 30% of fuel. U could have something like an exhaust leak,intake leak on bank 1 possable 02 sensor but u should also get an 02 code if it was bad and not performing right. Some one with a snapon scanner or DRB would see this.

 

Dodge Tech, thanks for responding.

Please help me understand. The computer is reading that the mixture is too lean, correct? If the computer is reading too lean incorrectly because of a bad sensor, it would compensate and force a mixture that is actually too rich, causing the black soot and missing, correct?

Thanks again.

--I don't mind throwing someparts and a little money at it if it means I can fix the problem myself.

Take care.

 

thats what i said the computer is making adjustments for the fuel that is not there And no the computer does not read what a mixture is only how much O2 is in the system b4 and after the cat.When a code for Fuel system Lean that means the computer is passed 33% on how much fuel is added. A RICH code is for the computer taking away more then 33% of fuel. Heres is a list of possable causes u can pick what u want to start with.

INTERMITTENT CONDITION
RESTRICTED FUEL SUPPLY LINE
FUEL PUMP INLET STRAINER PLUGGED
FUEL PUMP MODULE
O2 SENSOR
O2 SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
O2 SENSOR HEATER OPERATION
TPS VOLTAGE GREATER THAN 0.92 VOLTS WITH THROTTLE CLOSED
TP SENSOR SWEEP
MAP SENSOR OPERATION
ECT SENSOR OPERATION
ENGINE MECHANICAL PROBLEM
FUEL FILTER/PRESSURE REGULATOR (HIGH)
PCM

 

Thanks Dodge Tech. I'll let you know what happens.

Thanks again.

 

In depth explanation of how an O2 works and why Dodge Tech's advice is right on the money.

http://free-auto-repair-advice.blogs...what-they.html