D's Up

So, my TL's at about 104.5k . And I'm throwing a CEL. The weird part is that the CEL comes and goes as it pleases. . Sometimes it won't be there the entire drive, sometimes I turn it on and it's there, sometimes it shows up once the car is rolling. It's very "inconsistent", to say the least. lol. Anyways, here are the codes. I was wondering if there was anyway I could interpret them.

Code #1: PD134

Code #2: P2251

Anyone wanna' help your boy out? haha.

avs007

They are both for your Oxygen Sensor... P2251 is an open in the control circuit. P0134 is no activity from O2 sensor...

I'm guessing the wires to your O2 sensor is frayed, damaged, or disconnected, or something like that... Since you said it's intermittent, I'm going to guess it's damaged/frayed, causing an intermittent short/open or whatever...

D's Up

Well, I'm really tight on cash right now. What do I need to replace? How much would it cost? Can I do it myself?
Thanks for the answer AVS.

avs007

I've changed an 02 sensor myself, it's super easy... It's just I'm not sure if your sensor is bad, or if it's the wiring harness... Since it's intermittent, I was thinknig the wire was frayed or something, so maybe you'll luck out, and can fix it with some solder and heat-shrink tubing, or maybe even electrical tape and heat-shrink tubing...

Based on your username, I'm guessing you have an 04' TL.. But Acura of Peoria has the Oxygen sensor for $51.79. Here is a link to their online store.

avs007

Now that I'm home, I checked the CEL codes with the Acura Service Manual... (The descriptions above are generic OBD descriptions from google)

P0134 = Rear Air Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) Heater Circuit Malfunction
P2251 = Rear Air Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) VS Line High Voltage

I'll post the troubleshooting procedures in the next post...

avs007

Based on the troubleshooting steps, it looks like your codes are caused by a wiring issue, not a bad sensor.... You already said it only intermittently sets a code, so I'm assuming that answers step #4, which means you have an intermittent failure caused by a poor connection at either the sensor side or the ECU side of the harness...




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D's Up

so, is this something I could do at home or do you recommend that I just go to my mechanic?

avs007

Depends how comfortable you are with working with wiring... I would at least check the harness that plugs into the sensor, maybe it's just loose/corroded/etc... If it's that, then maybe you can simply clean it or whatever, and it'll fix it... If there's an actual short/open somewhere, that'll be trickier to find... If you go to a mechanic, you can probably print out the above diagnostics, and he can start from there... It doesn't look to be a very involved procedure, so hopefully it shouldn't be too much... Perhaps maybe one hour of labor tops... But I'm just pulling that out of my arse...

D's Up

Ok, I'm a noob with wiring. How would I check the harness that plugs into the sensor?
And seriously, thanks for the help AVS.

avs007

iirc, the sensor is on the front exhaust manifold. You should be able to just pop the hood and disconnect the sensor harness. I'm thinking the connector will be loose. Check to make sure the plug isn't rusted. Also check to make sure the wires aren't melted onto the exhaust manifold.

93notch

the heater circuit short makes me thing the sensor itself is bad.

D's Up

heater circuit short?

avs007

The first cel code is for a malfunction of the heater circuit on the oxygen sensor... The second cel code says that the first code is always set with the second one, and that you should troubleshoot the second one first....

In my opinion, if the sensor was bad, it should always set the light, not intermittantly. But if it is the sensor, it is very easy to replace.

D's Up

Bump, the CEL now comes around every so often but goes away after driving 5-10miles usually. Any DIY's on how to replace an O2 sensor? I just recently got my finances in order again so I need to replace my Spark Plugs (is this a possible DIY?) and figure out this CEL.

I hate cars

If it comes on mostly when you're driving very easy but goes away when you drive hard and get some heat into it, it's most likely the sensor.

It's as easy as unscrewing the old one, unplugging the harness and screwing the new one in and plugging it in.

Plugs are super easy in these cars. Remove the plastic covers near the firewall. No need to remove the shock tower brace. Remove the coil of the plug you're replacing one at a time. Find the combo of exensions and swivels that work the best for you and replace. Make sure to use anti-seize and if using iridiums check the gap. They will most likely be spot on already. It took me less than 30 minutes the first time.

D's Up

Thanks for the help IHC, I was hoping you'd chime in. I'll monitor the CEL tonight while driving around.

Where are the o2 sensors located on the TL? I've never actually known where to look and I've searched numerous times but haven't gotten an answer yet.

Thanks for the DIY on spark plugs as well man. I'll be using NGK Iridiums. I believe that's what they're called.

D's Up

Also, how can I check or tell if my engine mounts are broken?

I hate cars

The primary 02s which should be the ones you're replacing are located right before the precats near the engine. The front one should be easy. The back one is a little harder to get to but not too bad.

acuratech239

iTrader: (2)

FYI there is a service news from March '06 :

Faulty A/F Sensor Can
Cause Multiple DTCs
A faulty A/F sensor in a ’03–05 MDX or ’04–05 TL
can cause any or all of these DTCs to set:
• DTC P0134 [rear A/F sensor (bank 1, sensor 1)
heater system malfunction]
• DTC P0154 [front A/F sensor (bank 2,
sensor 1) heater system malfunction]
• DTC P2237 [rear A/F sensor (bank 1, sensor 1)
IP line high voltage]
• DTC P2240 [front A/F sensor (bank 2,
sensor 1) IP line high voltage]
To fix this problem, check the sensor wiring and
connections for damage. If the sensor circuit is
OK, and the DTC(s) come back after clearing
them and doing a short test-drive, replace the A/F
sensor. The replacement A/F sensors in Honda
parts stock are an improved version over the
original sensor.

I see this problem much more often on the MDXs then I do the TLs. Regardless, haven't had a come back yet after replacing the sensor

An OP, it's pretty straight forward and simple to replace either of them, front bank is of course easier, as others have said.