+1
sometimes even going to hiflow cats will still give you the CEL like you have no cats.
get a tune that shuts off you rear O2 sensors and you'll be golden.

 

You can't just get the rear sensors turned off if you have to go through emissions checking during inspection. They'll have to be in and appear to be "functional".

Zero, the code is telling you that the driver side front sensor is not producing any signal voltage. Check to make sure the green connector or any of the wiring did not get damaged. With this code, I would expect a cut or burned wire, or the sensor itself is bad.

You could swap the front sensors and see if the code changes to bank 1, then you'd know if the sensor is bad.

Rear sensors and cats, present or not and regardless of the tune, should NOT cause this code, if the code is correct and is indeed bank 2 sensor 1.

 

Here's an easy question, did you disconnet the battery for a few minutes and reconnect it? With 05+ cars they are very sensitive to changes. They do both long term and short term fuel trim ( how long to keep the injector open) Your computer may just have had to learn how to adjust for the new 02 readings properly.

Lean would make sense because with less back pressure the exhaust is moving faster (higher volume of air) so the computer is out of trim (adjustment) from what was previuosly being read and became expected. the light will go out on its own or pop back up immediately after reset if there is a real problem.

 

Clear the DTCs or disconnect the battery for 20 minutes to clear the codes. And doing a change such as what was done, doing this first is not a bad idea, unless the battery was already disconnected during cat removal.

It's possible the removal of cats could affect the fuel trims, a little. But one side would not be stuck lean (meaning, the PCM is reading 5 volts from the signal-side of the sensor; since the PCM provides that 5v, it would make sense that either the circuit is open between the PCM and O2 sensor, or the O2 sensor is open internally. 0V would be stuck rich, and likely a short or bad sensor.).

 

Thanks for all the help.I am going to have to check on it this weekend.

I do have a C&L street intake with Diablosport tuner and SLP loudmouths. I have cleared the codes with the turner but after a second start up they come back. I have 43,xxx miles on the car. I had a trusted shop do the work since I could not get the cats to loosen from the manifolds.

 

I now have a new message.

P0152 circuit high voltage (Bank 2 sensor 1)

 

Well it turns out it was the O2 sensor. Thanks for all the help.

 

Like I thought.

 

so just out of curiosity. has anyone done this on a mustang?? Thats from an Evo site. I would like to get an X pipe. Thought about high flow cats...but the price compared to an o/r x pipe makes me think differently. If this trick REALLY works and I dont have to tune or redo anything to pass emissions every year then Ill gladly go this route with the O/R