HI Folks,

I have an 08 TL type-S that has had the Check engine light on constantly for a few months. In the past couple of months I had the dealer clean out the ERG ports as they were trying to figure out the problem (they did find the carbon gunk as found in this thread). I currently have the following three error codes being thrown on my car (I pulled the descriptions from this thread):
P0138 Secondary Heated Oxygen Sensor (Secondary HO2S) Circuit High Voltage
P0404 Exhaust Gas Recirculation (EGR) Control Circuit Range / Performance Problem
P0430 Front Bank Catalyst System Efficiency Below Threshold (Bank 2)

The Dealership wants to fix it by swapping the following parts:
EGR valve (CAT)
Cat Converter )
Bank 1 Sensor 1
Bank 2 Sensor 2

I'd like to know if this seems legit and/or if there's anything else I should work on if they're already going to be doing this much labor. I tried searching the forums and it seems the sensors are probably legit, I'm more concerned about the Cat converter. Some comments from my service advisor for context:
My Erg valve isn't opening and he also suspects that my sensors are bad which is making the car run fuel rich.

 

I would do the egr first. it's unlikely everything failed at once.

 

they are related tho.
EGR is exhaust gas recirculation.
o2 sensors monitor air/fuel

and if one of those fail, a cat can fail...because a cat has to do with air/fuel/exhaust

so yes, they can all fail at the same time...because wrong octane fuel.

 

Thanks folks for the replies. It's helped a lot