triax37

iTrader: (1)

Hey everyone - I searched but couldn't find a schematic or garage post about how to replace the two front oxygen sensors. I'm throwing code P2251, so just ordered the new sensors and would love to put them in this weekend - car is at 90k miles, so I figured I would just replace both of them. Any diagrams to share? Thanks!

nfnsquared

P2251 is the REAR (not front) upstream (top) O2 sensor. You only need to replace 1 sensor. Unplug from the harness and then unscrew (33 ft-lbs)...

Removing the tower strut bar will make it easier (3 nuts each end, 21 ft-lbs), 2 bolts on right side, 1 bolt on left side

triax37

iTrader: (1)

Thanks - when I wrote "front" I was trying to separate from secondary sensors after the cat. Quick follow-up - what's the best way to reach Bank 1 - from the driver side? I just bought the car 2 months ago, so am learning exactly where everything is located.

nfnsquared

passenger side i think, haven't paid attention in a long time. You can see it between the rear of the engine and the firewall.

triax37

iTrader: (1)

Thank you sir!

leedogg

What are the part numbers for both 02 sensors?

Bearcat94

There are actaully 4. 2 upstream (pre-converter) and 2 downstream.


http://www.acuraautomotiveparts.org/...s=&view=normal

leedogg

muchos gracias

These should be them.

36531-RCA-A02 SENSOR, LAF
36531-RDM-A01 SENSOR, FR. LAF
36532-RKB-004 SENSOR, FR. SECONDARY OXYGEN
36542-RKB-004 SENSOR, RR. SECONDARY OXYGEN

Flick

Why just replace the one??? I'm at 134,000 miles and just trying to keep up on things, should I be replacing all of them with my mileage???

triax37

iTrader: (1)

Flick - the simple answer is cost. A new upstream O2 sensor will run you $120 or so. If you're noticing a loss of mileage, the O2 sensors are common causes. If you're still getting 30 mpg at 70 mph, then your sensor is probably working fine.

Keep in mind the computer is always checking the sensors, so if there was a big problem, you would get a Check Engine Light.

For those that want a writeup on changing the sensor, I put one together last week but put it in the "Problems & Fixes" subforum:
https://acurazine.com/forums/3g-tl-problems-fixes-114/e-130-diy-oxygen-o2-sensor-installation-rear-upstream-f-aka-p2251-811823/

neilsuacura

Acura RL 2005 got Code P0154 and P2254, Where can I got the Oxygen sensor for Bank 2, Sensor 1.

Many thanks!


Neil

JayRL

Did you have any symptoms before the car threw a code? have a 2005 Acura RL 165k miles that I've had for about a year now, lately I have been noticing that the acceleration is very sluggish. The car accelerates nowhere near as fast as it used to I have replaced plugs already with no luck, don't know what else it could be. No CEL

triax37

iTrader: (1)

Hey, I don't recall having any symptoms before the code was thrown, but it was 6 years ago... Has the throttle body ever been cleaned?