02 bank 2 sensor code, replaced nothing changed.

Need help, 2002 Toyota Tacoma 2.7l, throwing 02 sensor bank 2 code, i installed a brand new sensor. Starts and runs just fine first thing in the morning or after it’s sat for a few hours, run it for about 30 minutes and let it sit for a few minutes and it takes 3 times to start and idles rough. Then runs and drives fine. Any help is appreciated.

 

Sounds like a dripping injector or coolant leaking into the combustion chamber

 

Definitely not a coolant issue, and injector maybe, I haven’t checked them yet, I have been told that it may be catalytic converter or maf sensor

 

nobody said it yet, but yet giving advice...
What is this actual code # & description............?

 

^^^ what he said. I dont think the 2.7 has a Bank 2 O2 sensor. The code might be referring to Bank1 O2 sensor 2 (B1OS2) and if so this oxygen sensor does nothing but monitor if the catalytic conver is working properly and should have no effect on engine operation.

 

A clogged cat will create lack of power and struggle, a crumbled cat will create raw fuel smell regardless if the cat is hot or not.

On a T100 5vz I serviced a few years ago had this symptom, when cold, the truck turn over with no issue. But if you drive it 5 miles or 30 miles and turn the engine off for a few minutes, it took several cranking attempts before the engine turned over. The issue is when the engine heats up and turns off. If it’s parked overnight or long enough for the engine to cool down, there’s no cranking issue and will start on the first attempt. It ended up being his injectors, it was dripping and leaking into the combustion chamber, causing the engine to crank multiple times until the fuel cleared. Per MotorWest, 2 of the 6 injectors were dripping and not spraying while other 4 were in ok conditions. Bought 2 replacement from them while they cleaned the other 4. Reinstalled and no more starting issue. I’m not saying that will be your issue.

 

This year, I helped a neighbor with an E36 M3 with a B2S1 code. Thinking it was an easy fix, changed the sensor but the issue remained. It was not a multiple attempt crank but had to hold the key in the start position slightly longer than normal. After pulling the plugs, cylinder 5 was fouled bad, enough to create no spark and the raw fuel mixture was cooling the sensor. Changed plugs and issue went away. Likewise, I’m not saying this will be your issue.

 

or could be a p0420 or a p0430 that has NOTHING to do with an 02 sensor code....

 

I can’t remember exactly what code, but it was sensor 2 fault/ heating element fault.

 

got it, makes sense,
you may have a popped fuse....
The heater circuit may have internally shorted in the sensor to ground & popped a fuse, have seen that on a few fords....
or you put a cheap 02 in it...
Sometimes things need to be diagnosed & not just roll the dice..

 

I got a Bosch brand, it was 120$, and I took the temp of before the cat and after the cat with a good temp gun and it was over 100 degrees difference, so maybe my cat?

 

the heating element of an O2 sensor has nothing to do with the temperature of the catalytic convertor. On modern O2 sensors there is a bimetallic element the heats up very fast when the motor is started. This allows for the O2 sensor to start working within seconds of startup IF the system is in closed loop operation. The PCM is very sensative to the resistance reading of the heating element and not all aftermarket parts are compatable. I hope that your sensor fixes your issue.

 

So update, So Ive almost narrowed it down to the fuel pump, is the fuel pump supposed to prime when you turn the key on? And i put a gauge coming right off the pump and 0psi when they key is turned on, when cranking it goes up to 35 psi and right back down to 0 when we stop cranking. So it holds no prime.

 

have you tested ur FPR? I would look for anything to do with that before trying a pump and/or injectors.

 

How do you test your fpr?

 

You can look for fuel in the vacuum line on the top of the fpr. Fuel = bad. the diaphram is ruptured. if its dry its fine, then you should do some pressure test elsewhere. there's a couple different ways you can test and find where your losing pressure. I haven't ever had experience on my first gen, but I'm sure its very similar to other fuel systems so I would look it up on YouTube. Maybe someone else in here knows how else you can test.

even with no evidence of your fuel pressure dropping after the engines off, i would still argue this is a fuel related issue. Your on the right track.

 

The fuel pump does not prime when you turn the key to the ON position, only during cranking and motor running will the fuel pump be ON. IIRC 35 psi is on the low side, 41 psi comes to mind. This is one of those things, is it within specs, no, is it worth putting a pump in, maybe, if the pump is origial, well it is 20+ years old and should you replace it "just because", dunno. What I am afraid of is that 2 weeks from now the pump is going to take a dump and you are going to say I should have replaced it when I had the time, been there many times, you touch something and it goes bad.

With low fuel pump pressure you might experience lean codes in the future. It should hold some residual pressure and that it drops pressure immediatly isnt right. This might lead to an extended crank time as the pump has to fill the fuel line from the fuel draining back into the tank, does it all drain back, no, the filter will hold some.

 

FP only starts priming and pressurizing in 'springy' or last ignition key position
(only vehicle i have every worked on where this occurs)

35lbs ok...on low side
my 2RZ under hood LCE pressure gauge 2RZ reads 46lbs running and 39lbs after shut down....stays up for over 35lbs about 45mins after shut down. original FP but RM injectors from motorwest

i have been told that FP's are linear.....(they either work or dont work) but what do i know