Can somone give me some advice regarding a AF sensor problem. My car was rejected for inspection. I had autozone do a DTC code check and I have 2 codes.

DTC P0134: Rear A/F Sensor (Bank 1, Sensor 1) Heater System Malfunction

DTC P2251: Rear A/F Sensor (Bank 1, Sensor 1) VS Line High Voltage

I joined alldata and did get troubleshooting instructions, but I would need a HDS. My question is w/o going thru all the voltage checks is there another way to find out what the problem is ...or componet is causing the problem... (btw is there a fuse in this circuit)

I was thinking of just going ahead and changing out A/F sensor 1, but I can't seem to figure out where it it is located on the Eng., plus I'm confused between, AF sensor and O2 sensor.. are they one on the same.

If someone could post maybe some pics and instruction I would be very appreciative, I'ts just a matter of time before Im nailed for a rejection sticker.

I'm not cheap but don't feel like being raped by the dealer either! In case you are wondering on a scale of 1-10 by automotove mechnical knowlege is about a 4-5.... can do brakes, water pump, alt etc... but heavy electrcial debuggong no...

Thanks for any help..

 

The A/F sensor does the same job as an O2 sensor. Not sure if there is a significant difference.

#9 in the diagram is the picture of the sensor. You have two catalytic converters on your car. This is the sensor that is right before the catalytic converter on the 3 cylinder towards the windshield/firewall.

The connector will have 8 slots, but only seven wires. The Acura TL manual shows the HTC diagnostics too. I don't know how you can test the resistances of the sensor. You can try to inspect the electrical connector to see if it is loose or there are corroded pins?

The sensor will run ~$160 from the dealership.

 

very good this is correct i am a honda tech and this is perfect info make sure you buy a sensor from the dealer,cause aftermarket ones dont work and make the cars run differantly.

 

Refer to this thread, post # 3 and #7:

https://www.hondaaccordforum.com/for...ad.php?t=37865

 

Beginning with the ULEV engines in 1998, Honda began using the term "A/F sensor" when they use a wide-band O2 sensor. It's more sensitive & wider range but it still is really an oxygen sensor. And YES Rusty, it is a different sensor than the corresponding O2 sensor in a non-ULEV engine. If you want to buy it from aftermarket, you have to be real careful that you're not getting a simpler "normal" O2 sensor.

Later (2003+) they start using that type of sensor across the line, probably because of tighter EPA regs across all cars.