HI FLOW CATS & CHIP dont go together

[CKlasse]

Some of the hi flow cats I've installed on the CLK55, E55, C36, C280 and C43 had gone bad due to 'runnning rich.' After a few dyno tests, a set of brand new cat would MELT almost instantly.

The two cars that we dyno'd also have upgraded/reprogrammed ecm. :(

We went further by unprogramming the ecm back to stock and put a new set of cats.... fiola... No problemo. I strongly feel that the custom programming / upgraded ECM runs richer during WOT and causing these hi flow/ metallic cats to melt.

I thought I share this with you guys. If anyone else have the same experience, post up!

Moreover, does anyone has AFR guage or Pyrometer for their exhaust, and had dyno'ed their car?

Thanks!!

PS... READY FOR SEMA?

[714guy]

Hey Ken

this is kinda OT, but everytime after a drive, me car smells like l've driven WOT the whole drive. I dont know how to describe the smell but its not rotten eggs.
It use to smell like that after i drive hard, but now its everytime i drive and i drive like a wuss now, since gas is $$$. What do you think it could be???

Thansk

[Denlasoul]

Were these cars chipped after the exhaust change or chipped before?

If they were chipped before, then the chip probably is not accommodating the new exhaust. Chip tuning after the exhaust change allows the tuner to correct parameters for running to lean and such.

Do you think this could be a possible solution to melting cats?

[CKlasse]

714guy,

Did you change your gas before it start smelling constanstly? Addictive added gas can change AFR slightly.

Burnt out fiberglass inside your muffler can be another reason. Typically, fiberglass doesn't get burnt out 'til 100k miles.



Den,

The E55's ecm values are constantly monitored/manipulated. He does run on the richer side constantly - with/out the exhaust.

I am not an expert in ECM programming, but to my knowledge, those custom burnt EEPROMs usually do three major mods on the stock program...

1. AFR - going richer on the fuel map
2. Shifting point
3. RPM and Governor limiter

In short, they do make the car richer.

Correct me if I am wrong.

[J Irwan]

Actually

what 714guys experience I am 100% sure other have too..


After I drive my car in spirited driving mode, I always smellt something smell.... not like rotten egg more like exhaust smelt..


This is before and after my powerchip.
First I thought it was the brake or the clutch, but after repeated times, I am convinced that the smell coming from the exhaust..


so maybe under WOT the car is running a little rich..


Regardz,

[714guy]

J Irwan, i use to smell it under only WOT, but now its after every drive. But cool to see it might be normal.


C Klasse, My car is 106K miles already, does the burnt fiberglass affect any thing?? or should i now worry about it??

Thanks

[Denlasoul]

Programming usually falls into those 3 categories mentioned above. One thing that may also affect is the ignition timing and all that stuff. It is possible that WOT may have thecar running rich.

I guess the only way to tell is to monitor all that, but I dont know much about that process. :(

[2phast]

The rotton egg smell is a strong indicator that your cat is not doing its job and/or its bad. I removed my cat on my Corvette and wow, talk about rotten egg smell, even after a reprogram of the ecu (for no cat and Borla exhaust) it was better but still there.

My guess is its time to replace your cat, you might also have problems passing emissions

[CKlasse]

Originally posted by 2phast
The rotton egg smell is a strong indicator that your cat is not doing its job and/or its bad.


but its not rotten eggs

:D ;)

[MrSpace]

what was the A/F ratio on the cars that it melted

becaue I know I run richer with my new FPR and don'T want to ruin a cat if I change it

Etienne

[Rocky]

My question would be people with AMG tuned cars that included an AMG reprogrammed chip...are our cats safe?

[CKlasse]

A healthy AFR is 13.5-15. Some of these cars run as rich as 12.8-13.5. :(

[Denlasoul]

Originally posted by Rocky
My question would be people with AMG tuned cars that included an AMG reprogrammed chip...are our cats safe?

I guess that would depend if your current a/f ration is within the proper range. In not, then it may be possible it can go out prematurely.

[CKlasse]

A healthy AFR is 13.5-15. Some of these cars run as rich as 12.8-13.5. :(

[redc36]

just wondering how much high performance catalytic converter would cost for a 95 C36 and where to order. my car is at 105k and its been smelling more and more often.
Is the highperformance catalytic uses magnaflow cat with custom inlets and outlets. can someone explain. if its off the shelf product maybe i can simply buy it at any muffler shop.


also is fiberglass a replacable part? how much does it cost.

thanks

[Snake_99]

I just replaced my stock CAT with a Maganflow 94106, the difference in weight, sound and performance is incedible. Price installed at a local custom muffler shop was around $200.00. And the CAT comes with a 25,000 warranty!!:)

[CKlasse]

And the 94106 isnt even the highest flow they got ! :D Magnaflow rocks.

Redc36, where are you located?

[redc36]

Queens NY

r u close by? or maybe can recommend a shop where they have catalytic i need?
if magnaflow above is not the best one for c36 what model is?

[delisi2322]

i have two brand new cats i bought from cklasse that i need to sell email me if interested delisi22@sbcglobal.net