i got those 2 codes after putting the scanner on due to my car ideling really bad can this be a clogged cat i dont have headers or nothing like that. Please help ?

 

Just a guess but sounds more like just a sensor/wiring problem to me rather than a cat - is it rattling/glowing? P0155 is the passenger side precat 02 heater and P0161 is the passenger side post cat 02 heater. You have a pre 01 car? - not listed in my helms. You can look up the codes/diagnostics for your year at www.gearchatter.com if you don't get a quick answer. TTT for ya...

 

I love the guys that own a LS1 but never join our forum until something goes wrong...

fastbuff...probably just a bad sensor down there.