I have a reoccurring P0431 code and have narrowed it down to the catalytic converter for sure. I was going through some post on here and I found a single post that said there is an ECU upgrade that raises the threshold to get to get the light off and pass inspection. Is this bogus or is this my way out? Also, if this true, that still means the cat is bad and could cause other damage downstream, right?

and I also read that putting test pipe (that you keep in) is possibile??

 

you can have some custom software written that turns off the light. not exactly something you can do yourself or easy to find.

that code could mean either: the catalyst is bad/broken/clogged; the secondary o2 sensor isnt reading correctly; or you have a leak maybe, it would have to be a decent sized leak. there isnt really anything else downstream that can be damaged so dont worry about that.

you can put in a test pipe, but you would get the same code because there would be a problem with the cat still (problem being there isnt one). you wouldnt pass a sniffer during emissions test.

 

I see. Ive always gotten codes specific to 02 sensors when theyve gone out in my other vehicles. But I did consider that it may be the 02, which is why I am going to change it anyways. So I was quoted a grand for a cat installed. Do we need to use OEM, and is it something I can do myself instead? Never tried that one before.

 

you can buy a generic cat for $100 or so and pay any muffler shop $250 to weld it in there. a new OEM cat is going to be like $500 from a dealer, and a dealer is going to charge you another $400 to put it in. you can buy a high flow cat from labree motorsports (google it, among other places) for pretty cheap. if you have a ton of rachet extensions you can do it yourself. its not the easiest thing to do though, it took me about 6 hours to swap out cats in my driveway. it was one of the biggest PITA jobs ive ever had to do. you need to replace the two gaskets, and replace 3 bolts and 3 nuts on the cat>downpipe connection when you do the job. normally you can reuse the 17mm nuts and studs on the turbo>cat connection. soak all 6 bolts in wd40 the night before.

 

I am very glad that I can get a cat for much cheaper. The tech told me that using some aftermarket cats have conflicts with the computer and light comes on. Is there any chance of that?

A shop down the road from me installed my two magnaflow cats on my f150 for 150. I bought the cats of course. Are the audi cats a pain to get to, or will a typical muffler shop have no problem doing it? Some of them wont touch imports with a full exhaust overhaul.

Lastly, I like my exhaust as quiet as possible. If the aftermarkets give a slight throatyness at WOT then that is fine, but I dont want any drone.

 

I called Labree and they said you cant replace just the front cat, you have to replace the entire mechanism?? this goes against everything I have read on here so I am very confused now. I got a ticket today for my inspection and I have 7 days to get it renewed or I have to pay the fine, on top of still getting it fixed.

and now I just checked magnaflow and they dont offer them for our vehicles?