My 03 ranger runs flawless 90% of the time, but occasionally it runs rough and throws code, 02 sensor bank 1 sensor 1/2 voltage to high, the roughness does last long and clears up as soon as the throttle is cracked, any ideas? Fuel pressure is about 68 psi

 

Whats the code?

O2 sensor bank 1 sensor 1 is passenger side closest to the engine
Bank 1 sensor 2 is the O2 behind Cat converter

High voltage means Rich running Low oxygen in the exhaust

O2 sensor voltage is .1 to .9, so under 1 volt, .1 is lean, high oxygen, .9 is rich, low oxygen, computer adjusts OPEN TIME on the fuel injectors to try and keep Upstream O2 sensors(sensor 1's) at .4 volts
O2 sensor generate their own voltage once they are above 600degF, this it by a chemical reaction, so the chemicals do get used up, 100k miles is recommended change time
Upstream O2 sensor voltage should change rapidly, between .2 and .6 but average .4

Sensor 2, Downstream O2, should should run at a steady .7 to .8 volts, this is because Cat converter has burned up most of the oxygen while cleaning up the exhaust

Sensor 1 high voltage means computer has tried using less fuel on bank 1 but O2 voltage was staying high, but you should also get a Rich Code

Need the exact code to really determine whats happening

 

I will pull the code tonight soon as I am back at the shop and will update accordingly, thank you

 

Code showing are
P0141
P0720
P01131
P01515
P0135

 

You should post definitions with the codes since you probably already looked them up, lol


P0135 02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1), passenger side near engine
P0141 02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2), passenger side behind Cat Converter

Check Fuse #41 in Engine bay fuse box, it powers the O2 heaters
Assume manual transmission?
And this is a V6 engine, right????

Because I would expect code P0155 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1), driver side near engine
If the fuse was blown, if its a 2.3l 4cyl engine then it only has the two O2 heaters

Each O2 sensor has a heater built in, the computer monitors the heater voltage, "Circuit malfunction" means no heater voltage


P0720 Output Speed Sensor Circuit Malfunction
This sensor is at the rear of the transmission, unplug it and check the connection, could just be loose or dirty

P0xxx codes are generic, not Ford, GM, Honda, ECT...........specific

P1xxx in this case are Ford specific, not generic
So never Google P1xxx codes your will get the wrong answer most of the time

P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1, passenger side

P1515 Electric Current Circuit

Both of these can be from Fuse #41 being bad, so you need to check that first and find out why the heaters are off line