i just recently got my car tuned and i do have long tubes with an off road x. a little while after driving my check engine light came on and throw the DTC of P0133. i have searched the forum and found that it's most likely the LT's because the o2's are further away. anyway, here are my questions.

1) it is dyno tuned and the a/f ratio is at about 13.2:1, what can the tuner adjust so this code will not appear again? i have heard that to fix this you have to get it tuned, but my car is tuned and still throwing the code.

2) when the check engine light is on is my car in limp mode or anything which causes bad gas milage and lower HP?

 

This code refers to the passenger side front 02 sensors being relocated further down the exhaust stream than the original factory location and is slow to respond and to communicate with the pcm as a result. This can be tuned out by adjusting thefront02's transport delay. This is a very common code for longtubes and is easily fixed in the tuning.

 

^^^^Sums it up.

Driving with the light probably isn't going to hurt anything, but I would return to your tuner and have the issues worked out.