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obd-ii question. What is "bank 2"?

1176 Views 13 Replies 9 Participants Last post by  Grog6
So, I pulled the codes from my son's t-bird. The error is P1151 (upstream O2 sensor, left bank).

My question is this, "what is bank 2"? Are they talking about passenger/driver side, or something else? If it is the side of the vehicle, which side is bank 2?

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I'm not sure which bank is 1 and which one is 2, so I can't answer your question. But I had to answer so I could say "welcome to the boards" and I love your user name. I'm sure that, in spite of the old saying, we can teach you some new tricks. :D

I can tell you that "left bank" is the drivers side, just in case.
I've had a downstream O2 sensor failing on bank 2 ever since I bought the car 3+ yrs ago. I looked into it ages ago and seem to recall bank 2 being the passenger side, but take that with a grain of salt.
Bank 2 is the drivers side on the 4.6.

Bank 1 is the side that has cylinder #1, and that is the passenger side on the 4.6.

So if I understand this code, it appears to mean that the drivers side bank is running rich and the ECC is trying to compensate. Can someone help me prioritize my troubleshooting?

According to This condition can be caused by any, or several, of the following. I'd like to get an idea of which would be the most probable root cause.

* Short to VPWR in the harness or HO2S
* Water in the harness connector
* Open/shorted HO2S circuit
* Corrosion or poor mating terminals and wiring
* Damaged HO2S
* Damaged PCM
Fuel System:
* Excessive fuel pressure
Leaking/contaminated fuel injectors
Leaking fuel pressure regulator
Low fuel pressure or running out of fuel
Vapor recovery system
Induction System:
* Air leaks after the MAF
* Vacuum Leaks
PCV system:
* Improperly seated engine oil dipstick
EGR System:
* Leaking gasket
* Stuck EGR valve
* Leaking diaphragm or EVR
Base Engine:
* Oil overfill
* Cam Timing
* Cylinder compression
* Exhaust leaks before or near the HO2S(s)
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If it is the only code you are getting, it is likely specific to that one bank, so anything that is upstream and affects both sides can be put lower on the list to check.

I would guess look at the wiring to it first, the O2 sensor itself, then vacuum leak and fuel. If there isn't any drivability issues that is. If there are drivability issues then I would look more towards fuel delivery and vacuum leaks.
Thanks, That makes perfect sense. As soon as it stops raining, I'll start digging in.

I just saw that you have a 63 Falcon. That was the first car I ever owned. Mine was a six cylinder, three speed on the column, though. I loved that car. No rust, faded blue paint, torn seat upholstery, cracked dash board, oil circulation issues and all. After a bunch of years, I burnt a hole in the top of one of the pistons and practically gave it away.

If I knew then what I know now.

Holy thread drift....I had a 1960 Falcon wagon.

I got a Catalyst System Efficiency Below Threshold bank 2 (P0430) which the guy i bought the car from said it was the 02 sensor. Gave the car a tune-up and its never came back.
I had that code on both my cars, but different solutions. the first time the wires on my o2 sensor coroded. the second time it was a dirty maf, i picked up some maf cleaner at advance and spayed it like 12 times or somthing. o yea plus a vaccume leak, that usally throws that code
Bad o2 sensors...Replace both the front ones at the same time...the bosch ones from the zone suck...the second set I bought factory, works great.

The rear ones just check the cats; if they go bad, it can pull down the power on the system, I swapped them for the pos bosch ones and no trouble now.

I thought bank 2 was passenger side; maybe that's what caused me so much grief...:mad:

If both banks show trouble, it's usually the maf...if it's lean, check for vacuum leaks.

That is pretty much everything I've ever had to do to these cars' engines except for plugs, wires, and one IAC...

I had a '63 and white...I still can't believe I sold it...:xpcry:
I still have the title; last time I looked it up it belonged to a movie company in CA...
I have a 63 Thunderbird.

And bank 2 is something that I have showing on my car too. Nice info here.
I have a 63 Thunderbird.
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