Sam Woodson

I searched back through this Sub forum on B7's, I didn't see anything in the last two years on Cats.

66,000 miles, Engine code states Bank 2 Warm up Catalyst efficiency was below threshold.

Code P0431

One show said for $100 they would diagnose/test it to verify it's not just an O2 sensor. Thoughts? They gave me a quote of $2,185 to do both sides (not sure if that included O2 sensors). Another shop said $2,100 or $2,650 with O2 sensors.

I don't want the car to be louder in the cabin and I definitely do not want any droning. Also, I want to make sure I don't have a CEL on all the time, how would you know if something really happened if it's on all the time.

So, would the Piggies with the Pre-Cats gutted meet this requirement? Otherwise stock exhaust as far as I know.

Audi quoted $600 labor, but over $3000 for parts.

If Piggies would work for me, what brands fit the best, last the longest, and they price wise where are they?

If not what about the aftermarket Cats from Magnaflow? How do they hold up? Or is there another brand I should look at?

Thank you,
Sam

bonehead2412

IVE de-catted my s4 4.2 v8 yes it louder but when you drive with the windows up can't tell the difference as long as your not driving it hard

ive had straight pipes welded in place of the cats and new flex joint

played with map and tune to remove the fuel that injected in to the cylinder on the exhaust stroke to keep the cats warm and to make the car (quitter) plus I get much better mile per gallon 38 - 42 mpg on a long run plus it puts out less emission and less co2 than with cats

and the a brand new 2018 1.0 TFSI puts out more co2 HC than then my 4.2L V8 and that what audi said the could not believe the test and sent it for a retest at an independent test station to check the results and they match