Replaced bank one

Scanner showing bank one 02 sensor. I replaced it now the fuel is burning rich and only getting 10/mpg. 2003 tacoma prerunner v6

 

Howdy,

Scanner showed WHAT on bank one O2 sensor? Rich? Lean? Dead? Stuck? Voltage low or high?

What is the new code?

Did you replace with a direct replacement, such as a oem, acdelco, or Denso? The universials available from most part stores are nothing but a hastle and create more problems.

Bank 1 I do believe is passenger side, correct?

 

P0171 fuel system too lean bank 1 ...not sure about voltage
I did not replace with a direct replacement...i just purchased what came up online from an online store. Maybe that's my problem

 

Yeah, it is a possible variable we should eliminate. Try Amazon/rockauto and get a direct replacement denso unit. They made alot of our trucks electronics and I would consider them a oem.

 

Ok thank you. I will try the new oem one and let you know.

 

P0171 usually means you have a vacuum leak somewhere, which could also be causing your bad mpg. Check all your hoses for cracks/connections.

Could also be a dirty MAF sensor, o2 or air/fuel sensor, or possibly a crack in your exhaust. But check your vacuum lines first, and the MAF sensor is really easy to clean (just do it carefully)

 

I have this code too. I get it ALL THE TIME. P0171. When I clear it, it ONLY turns on during heavy acceleration and/or when you're climbing a steep grade. I have terrible fuel economy too. I tried cleaning the MAF but it was clean. I don't know what's causing it.

 

like stated above check for vacuum leaks first...

does your brake pedal firm up immediatly after you turn the engine off or can you get 2, maybe 3 pumps on the pedal before it gets hard? The vacuum booster could be leaking.

most of the time prior techs attempt to reuse the metal gaskets that seal the intake(s) with some sealant ... i.m.h.o., factory metal intake gaskets are the only way to go, the aftermarket ones have a tendancy to pull through and cause an vacuum leak.

 

Vacuum leak I bet

 

I received the sensor and it won't unscrew from the bracket. This is bank one sensor one upstream. The old one unscrewed out of the bracket. I can't mount this as the studs broke and the muffler shop closed the original hole and welded the bracket in place over a new hole he opened. Did I get the wrong sensor again?

 

Where's the gasket? There's suppose to be a gasket? Could that be the issue?

 

Gonna have to take some pics so we can see what you working with

 

This one didn't come with a gasket...weird. pics of the mounting location by the cat?

 

Just occurred to me also that if its happening under heavy throttle and your gas mileage is suffering, you may be looking at a bad air/fuel sensor which is another common cause for a P0171 code. Faulty O2 sensors can cause it as well.

 

Just in case this may help someone else...the Denso brand for bank 1 sensor 1 upstream has the bracket permanently attached whereas with the Bosch brand the sensor and bracket are threaded and separate. The Bosch part number for OE fitment is 13998 or 13613

 

oh!!! so thats what happen. You're now using a different type, well it still operates the same but the dude probably didn't fill in the original opening properly which is probably leaking.