Stinking check engine light!

[AJ02]

I was getting a check engine light about every 4 or 5 times I would start the car. Always for bank 1, sensor 1 O2 heater circuit. I replaced both front sensors with the Denso sensors from Rock Auto. Cleared the code again, and the third time I got in the car----same thing again!!! You recon I have something wrong with the PCM? Art

 

[mjorgensen Woodhouse]

Could be a wire issue not the actual sensor, look at the loom for burnt/melted wires and possible "chew marks".

 

[AJ02]

Last time I had it on the lift I checked as far as I could see and all looked good, but I'll throw it up in the air again tonight and look a little more thoroughly. Thanks, Art

 

[LifeIsGood]

Art...I forgot whether you have an aftermarket exhaust or stock...which?

 

[AJ02]

Stock. Bank 1 is the driver's side, correct? Actually, I replaced both sensors but the code is for bank1, sensor 1. In the manual it's called out as left = bank 1 and driver's side is left blinker, so I would think the two would match?? Piut it on the lift as soon as I got home from work and all wiring to both front sensors looks almost new.

 

[AviP]

Just to clarify, Bank 1 Sensor 1 is the driver side front O2 sensor, located under the exhaust manifold. There's no need to change the passenger side for that. Generally, Bank 1 refers to the same side as cylinder 1 on a V-engine. In the Viper, that is the left front cylinder.

What is the specific code you are getting?

 

[Jeffsss]

mine goes off and on for no given reason.. I'm sure it's c02 related but it drives me nuts.

 

[AJ02]

I can't remember the specific code # but it is for Bank 1, Sensor 1 heater circuit failure. Both sensor heaters run off the same circuit in the PDC, at least according to the wiring diagram in my service manual.

 

[uvbnbit]

when it comes to sensors, I recommend using OE.

 

[AJ02]

When I bought the car last year, it had new OEM upstream sensors and still got the same DTC. When I test drove the car, the check engine light came on for the same code described earlier. The dealer took the car to a Dodge dealership where they replaced both upstream sensors. It was about 4 or 5 days of driving before I got the code again.

 

[LifeIsGood]

Hey Art...do us a favor and get a reader to check the code(s) again...maybe something else popped up. A stock system shouldn't be killing O2 sensors that fast.

 

[AJ02]

No problem. I have a reader, I just forgot the code #. I'll have to wait till it comes on again. Might be a few days. Actually, I just had a moment of clarity and I'm pretty sure it's PO135- O2 sensor bank 1 sensor 1 heater circuit malfunction.

 

[GTLaser]

when it comes to sensors, I recommend using OE.

I agree but also your local Autozone or Advance will warranty these sensors for a year....

 

[AJ02]

Well, I got the car on the lift again this morning and found that the harness to the sensor was melted a little up around the A/C compressor. none of the wires were actually melted together, but I seperated them and put split loom around them individually. We'll see if that took care of it. I guess even if the insulation wasn't melted all the way through, current could still transfer. While I was under there, I decided to go ahead and install my Woodhouse motor mounts. That was fun!! Already put the trans mount in a couple months ago.

 

[AZTVR]

I guess even if the insulation wasn't melted all the way through, current could still transfer.

Not really. You have to have exposed conductors touching. However, the teeniest tiny exposure can be enough, and maybe the melted insulation flowed back over the exposed conductor when the wire (or engine ) moved.

83% chance that was it. (For me, the probability would only be 21%, since I often seem to find 2 defects for a difficult problem, and the first one is never the cause.)

 

[AJ02]

Yea, I got doubts too. It's never that simple. I'll just have to drive it and see if the code comes back.

 

[AJ02]

Well, I thought i was good untill today. I started the car and the check engine light came on again. All times before it was bank 1 sensor 1. Today it was bank 2 sensor 1. it seems I can't win.

 

[LifeIsGood]

When I had my P0135 (bank 1, sensor 1), I swapped the pre-cat (front) sensors and my code changed to P0155 (bank 2, sensor 1)...just like yours...that let me know for sure that the sensor was bad. I know that you did some work on the wiring...was that for the driver side only? Did you also look closely at the passenger side wiring? I'm just talking (typing) out loud here.

 

[AJ02]

Just got the car off the lift and the only thing I found was about a 1/8" place on the harness going to the driver's side sensor had sort of stuck to the A/C compressor. I guess it gets pretty hot in 100 degree weather. Don't know if that was it or not, but I put some loom around the harness to keep it away from the compressor. We'll see. I'm not sure how the computer differentiates between the bank 1 and bank 2 heater circuits. According to the schematic in the service manual, they both run off the same wire?? Unless the wire for the bank 2 sensor is tied in at the plug for the bank 1 sensor and just runs across to the other side. ******!!

 

[Jack B]

What is common to both is the ground wire. It starts behind power steering pump moves to the front of the pump and then goes to the passenger side. You can easily see if it is a bad ground by grounding the O2 sensor ground wire to the engine block. I had a similar problem and grounded both sides to the block.

 

[AJ02]

Acording to the schematic in my service manual, both the ground and power wires for the heaters are common to both. The wire coming from the relay splits off to both but the drawing doesn't really show where, which is common on schematics. They just show the general path and don't get onto specifics a lot. They might tie together at the relay, or maybe at the #1 sensor plug. The way the # 1 sensor harness runs between the engine and the A/C compressor, it's hard to get in there and work or even see much for that matter.

 

[vprtech]

The ground wire ends up at a ring terminal at the A/C compressor, that is, the wire should be terminated by one of the A/C compressor bolts.

 

[AJ02]

You are correct.