Catalytic converter error code with tune.

[Eundercoffler]

Hello All,
Hoping you can help me out here. I have a 2015 S4 with 100,000 miles. It has both an engine and transmission tune from European Performance Labs which were both installed when I got the car at about 60,000 miles. I did reach out to European Performance Labs but apparently they have closed up shop and I have not gotten a response. Anyways, ever since I put the tune in I have been consistently getting two check engine lights. I get one for over-rev which I am sure is due to the red line bing raised with the tune and the other is "Catalyst System Efficiently Below Threshold" (both banks 1 and 2).
So my question is, could the catalytic converter error codes be related to the tune (maybe hotter exhaust gasses) or should I look into replacing the Cats. If so does anybody have any suggestions for cheap cats? (I live in CA so keep that in mind).

Thanks,
Eric

[Fresh.S4]

cats going bad is p0420/p0430

the over rev only happens if you've over revved it hard. can you flash back to stock and see if codes return?
if your gonna pull the cats, go with CAP test pipes and get the discount from 034 for swapping to their files (they'll have test pipe files) you'll just need to find youself a smog guy...

[Eundercoffler]

I appreciate the suggestion Fresh.S4 but I need to be CA compliant on the Cats and it sounds like what you're saying isn't. Also I am aware that the p0420 and p0430 codes are the ones associated with the cats. My question had more to do with whether or not the tune could be causing them. As far as flashing back, I can not currently do this as European Tuning Labs appears to have closed their doors and has yet to respond to my emails.

[onlyaudis]

no cheap CA compliant cats unfortunately. I think these are the cheapest https://www.magnaflow.com/products/4...onverter-49136 I ran EPL stage 1 for 4 years with no CEL's. I took it off though as it will get flagged at smog now with the new ECU tune checks they are doing, (and since EPL went under) and went with 034's CARB approved stage 1.

[Fresh.S4]

apr stage1 with stock cats passes with no problems.
but i digress... best option would be to hit up 034 and change toons for that low $650.

[Eundercoffler]

The magnaflow ones specifically state that they are not for sale in CA.

[Fresh.S4]

The magnaflow ones specifically state that they are not for sale in CA.

ship them to someone outside of cali and have them ship them to you.

but still your best bet is getting test pipes + aftermarket cats and run them further downstream, because ANY cats you put in the oem spot is bad news...

[Eundercoffler]

I have to be able to pull the tune and pass smog so I don't think putting a non CA compliant cat in will work for me (unless I am missing something, in which case please enlighten me). However Fresh.S4 you did make a comment I am curious about. Why is having the cats in the stock location bad news?

[ccssid]

I have to be able to pull the tune and pass smog so I don't think putting a non CA compliant cat in will work for me (unless I am missing something, in which case please enlighten me). However Fresh.S4 you did make a comment I am curious about. Why is having the cats in the stock location bad news?

The new cats in stock location will get trashed just like your stock cats...from excessive heat.

[Fresh.S4]

I have to be able to pull the tune and pass smog so I don't think putting a non CA compliant cat in will work for me (unless I am missing something, in which case please enlighten me). However Fresh.S4 you did make a comment I am curious about. Why is having the cats in the stock location bad news?

with a new toon, (like 034) you can change files from test pipes to running a smog legal stage1.
but in general any stage1 should still be able to pass with oem cats. apr is good, i know that but i wouldnt suggest them (unless you get the full stage1 suite)
also the supercharger just creates too much heat and the cats are too close and have to absorb all that heat. also aftermarket cats are metal and not ceramic so more chance that the pressure will cause them to cave in (aka redstar catted/ or any other brand that uses gesi in oem spot)

[Eundercoffler]

I see, so it's a heat issue then? So if I am understanding you guys correctly, what some people are doing is putting test pipes in the stock cat location and then running the cats further downstream to allow for more heat dissipation? Is my understanding correct?

[JRYtheS4]

I see, so it's a heat issue then? So if I am understanding you guys correctly, what some people are doing is putting test pipes in the stock cat location and then running the cats further downstream to allow for more heat dissipation? Is my understanding correct?

It's completely possible to run a tune with stock cats on a street car. It's how you drive it and what tuner you chose.

Sent from my SM-G991U1 using Audizine Forum mobile app

[ccssid]

It's completely possible to run a tune with stock cats on a street car. It's how you drive it and what tuner you chose.

Sent from my SM-G991U1 using Audizine Forum mobile app

I see, so it's a heat issue then? So if I am understanding you guys correctly, what some people are doing is putting test pipes in the stock cat location and then running the cats further downstream to allow for more heat dissipation? Is my understanding correct?

I fit JRY's description. Approx 30k miles on APR's single pulley tune (93 octane) and still on my stock cats. Recently went to dual pulley (187:57). I have had my eye on this thread:

https://www.audizine.com/forum/showt...ange+test+pipe

[JRYtheS4]

It's the reality of living in a state where you have to pass visual and emissions testing. I'm in NY and I won't pass unless I go find some shady shop. I did that to get my tint passed and ended up peeling it this year because the guy got shut down. They're cracking down on shops fudging inspections here. I'd love to put in my test pipes and jhm catted baffled down pipe but I'm not going to do it until I actually have a problem.

The way I drive, my exhaust never sees more than about 1450F. I don't street race or go to the drag strip. My car's been over 100mph 1 time since I've owned it. I just mod it for the light-to-light fun. It's IE single pulley 93.

Sent from my SM-G991U1 using Audizine Forum mobile app

[Fresh.S4]

It's the reality of living in a state where you have to pass visual and emissions testing. I'm in NY and I won't pass unless I go find some shady shop. I did that to get my tint passed and ended up peeling it this year because the guy got shut down. They're cracking down on shops fudging inspections here. I'd love to put in my test pipes and jhm catted baffled down pipe but I'm not going to do it until I actually have a problem.

The way I drive, my exhaust never sees more than about 1450F. I don't street race or go to the drag strip. My car's been over 100mph 1 time since I've owned it. I just mod it for the light-to-light fun. It's IE single pulley 93.

Sent from my SM-G991U1 using Audizine Forum mobile app

im pretty sure many folks had their cats go bad without warning (thats kind of why theirs that big disclaimer of driver beware when it comes to having cats installed in the oem location) as long as everyone knows theirs risk involved. maybe a little, maybe a lot, maybe none at all. just be aware and remember p0420/p0430 are your first warnings if it pops up.

ill check my temps but im pretty sure 1400*ish +/- is normal at wot.