04 S4 check engine light codes

[theking]

hey guys

I ran over a construction cone the other day :/ and then my check engine light came on...i lost my lower grill and dented my radiator and that black box that sits in front of it...and ever since then the check engine comes on sporadically...i went to autozone today to get it scanned and heres what came out..There were 2 codes:

p0421 - catalyst efficiency low - bank 1
p0431 - catalyst efficiency low - bank 2

they both have the same explanation and possible causes:
explanation - the oxygen sensors monitor the catalytic converters ability to store oxygen

causes -
1. catalytic converter defective (could be due to #2, 3, or 4)
2. engine misfire or running condition
3. large vacuum leak
4. engine oil leakage into exhaust valve guide seals and piston rings

now i find it hard to believe that BOTH converters went bad at the exact same time as my hitting the cone, and i doubt there is a vacuum leak since it runs fine...however, sometimes when i start the car it is a little shaky so i could believe that there is some type of misfire, but im not sure..

Any help or advice is greatly appreciated!!!

[trexturk]

well, running over a cone wont make the converter light come on. you can take the car to the dealer and they should replace it for free for 8yrs/80k miles
Out of the 4 cats on the stock s4 exhaust, the top the only cats that will make a cel come on are the top 2 right off the motor. You might wanna check the rear o2 sensor/wires.

[theking]

it doesnt have the stock exhaust, its got an AWE exhaust on it...is that still under warranty? i know my 3 yr warranty is over

[theking]

also, how do i check the rear o2 sensor?

[theking]

any help?

[trexturk]

if you got awe downpipes they might have gone bad. sport cats usually go bad pretty quick
Just check the wires, make sure they aren't cut or anything