O2 sensor circuit slow response......again!

[Carfax83]

Driving home tonight, my CEL came on. As soon as I got home, I plugged in my diagnostic tool, and it showed a P0153 code, which means bank 2 sensor 1 O2 sensor circuit slow response.

This is the third time I've had both that code, and the P0133 code which indicates bank 1 sensor 1. For the first two times, I simply changed the O2 sensor. But now there's no way I think the sensor is bad.

It has to be something else causing that code to be generated. An exhaust leak perhaps? But if there was an exhaust leak, wouldn't I smell or hear something?

I'm going to have the guy that installed my headers check the bolts on Thursday regardless, but I don't think it's a leak..

What else could cause something like this, and how should I go about dealing with it?

 

[HarryLui]

Make, year, model

 

[Carfax83]

Make, year, model

Oh right. 2008 dodge charger RT with full aftermarket exhaust, among other things.

How small can a leak be to cause a CEL?

 

[hanoverphist]

when you put the aftermarket exhaust on, did you put an extended tube in front of the o2 sensors?

 

[Carfax83]

when you put the aftermarket exhaust on, did you put an extended tube in front of the o2 sensors?

No.. The codes that are being generated concern the upstream sensors that plug directly into the headers. The ones you're talking about are the downstream sensors that monitor the catalytic converters I believe..

 

[JeffreyLebowski]

If the new headers tube length is different at all from the flange to the O2 bung, the timing of exhaust gases to the 02 sensor will be off, thus causing errors.
So if the tubes are to long or they used an extra thick gasket it could be off enough to cause sensor reading issues.
Remember, the sensor only measures the particulate count and the computer knows when the spark was and the time it SHOULD take to reach the sensor. So if the particulate count is ok, but reached the sensor late, the computer would think something is wrong.

 

[Carfax83]

If the new headers tube length is different at all from the flange to the O2 bung, the timing of exhaust gases to the 02 sensor will be off, thus causing errors.
So if the tubes are to long or they used an extra thick gasket it could be off enough to cause sensor reading issues.
Remember, the sensor only measures the particulate count and the computer knows when the spark was and the time it SHOULD take to reach the sensor. So if the particulate count is ok, but reached the sensor late, the computer would think something is wrong.

Is this problem likely to occur with short tube headers as well, because thats what I have.. Long tube headers are more likely to throw codes from what I hear.

 

[Railgun]

The short answer is...

If they're in a different location from the port, or the diamater of the pipe is different...or both, then the air getting to the sensor will be different thus you'll need to compensate.

 

[Carfax83]

OK, the CEL went off by itself

The only thing I did different was I filled up with Exxon instead of Chevron like the last time.

Kinda makes me think of something an Autozone employee once told me, that fuel additives can shorten the life of an O2 sensor, or cause them not to work properly.

I also remember reading some advice from a guy on another forum to never use Shell or Chevron with a predator tune, because they put too many additives in their gas which screws up the octane or something.

Anyone ever heard anything like that? I have noticed that I've gotten slightly better gas mileage with the Exxon supreme, so maybe it's true..

 

[heymrdj]

Short tubes can most definitely cause the error you're seeing. Has your engine been reprogrammed?

 

[Carfax83]

Short tubes can most definitely cause the error you're seeing. Has your engine been reprogrammed?

Yeah, I'm running a tune... Diablosport Predator 93 CAI tune to be specific..

 

[heymrdj]

Have you tried a reflash?

http://www.300cforums.com/forums/sr...dator-wont-disable-rear-o2-sensors-moved.html

 

[JeffreyLebowski]

Have you tried a non Dodge product? j/k. IT very well could just be your tune doesn't like a certain gas blend. If you aren't racing the car on a track, I'd go down to an 87 octane tune and save the money each fill up.

 

[Carfax83]

Have you tried a reflash?

http://www.300cforums.com/forums/sr...dator-wont-disable-rear-o2-sensors-moved.html

You mean flash it to another tune? Or just reflash the same tune? I reflashed about 3 weeks ago when I installed the new O2 sensors..

Have you tried a non Dodge product? j/k. IT very well could just be your tune doesn't like a certain gas blend. If you aren't racing the car on a track, I'd go down to an 87 octane tune and save the money each fill up.

I'm seriously wondering if I could be overdoing it with the fuel additives. I use the Techron concentrate every 3,000 miles or so, but I also use premium fuel, which typically already has a fair amount of fuel additives in it. I think I'm going to lay off the fuel additives for a good while.

I also notice that when I use Shell V-power, my car feels less powerful, and V-power has more fuel additives than any other gas.

As for dropping down to 87, I'd have to go back to stock tune for that....and there's no way thats happening.

Besides, even though I pay more per gallon for 93 octane, I definitely get better gas mileage with it. I'm routinely surprised at how good of a gas mileage I get in my car.. It should get even better once I go with straight pipes again.. :sneaky:

 

[Railgun]

The differences you feel between blends is a placebo. While there may be a difference, it's not enough for you to feel. We're talking maybe 5hp.

 

[Tim_Derr]

Just get some o2 simulators.
did that on my hemi, no error codes since

 

[Carfax83]

The differences you feel between blends is a placebo. While there may be a difference, it's not enough for you to feel. We're talking maybe 5hp.

It's possible that it's a placebo, but I doubt it. When I filled up with Shell the last time, I didn't expect my car to lose power, but it did feel less powerful.

I don't think it's due to the gas itself, but the fuel additives. I think my overuse of fuel additives is screwing with my predator tune or the octane rating in the fuel.

I had used a bottle of techron concentrate for a 22 gallon tank when I filled up with the V-power, and thats why I think my car lost power and eventually triggered the slow O2 sensor circuit error code.

Just get some o2 simulators.
did that on my hemi, no error codes since

And that doesn't affect performance on the upstream sensors? The upstream ones are vital to the car's performance, unlike the downstream ones..

 

[Tim_Derr]

And that doesn't affect performance on the upstream sensors? The upstream ones are vital to the car's performance, unlike the downstream ones..

I changed all o2 sensors to simulators back in 2009. I get like 19mpg all highway with mds disabled.

I think it must be a bad tune.