Viper Scot
Viper Owner
This was spat out of my exhaust earlier this week...
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Exhaust vomit!
- Thread starter Viper Scot
- Start date
pattymelt3605
Enthusiast
Time to replace your catalytic converter...
Viper Scot
Viper Owner
The car had Random Tech high flow cats put in about 9000 miles ago. Going to go for sturdier ones now (or none at all!).
cyaford
Enthusiast
Better knock out the other side so they'll be equal. 
Great, Friday-nite on a holiday weekend. Strange claim. Random Closed. IF THEY ARE RANDOM TECH CATS they OBVIOUSLY did not puke out like that. Crash Damage? I have asked RT to check this out TUESDAY.
IF THEY ARE RANDOM TECH CATS They have a 5-year, 50k mile written warrantee, even in UK.....I suspect sometghing else at play here....... anxious for facts and solution Tuesday
IF THEY ARE RANDOM TECH CATS They have a 5-year, 50k mile written warrantee, even in UK.....I suspect sometghing else at play here....... anxious for facts and solution Tuesday
RapidTransit
Enthusiast
Hard to tell the dimensions in this picture, what are they?
scratch that.....im betting this had something to do with it.
http://forums.viperclub.org/rt-10-gts-discussions/638878-engine-management.html
but if not, this did for sure.....
http://forums.viperclub.org/rt-10-gts-discussions/624828-pics-my-rt-10-rebuild-saga.html
http://forums.viperclub.org/rt-10-gts-discussions/638878-engine-management.html
but if not, this did for sure.....
http://forums.viperclub.org/rt-10-gts-discussions/624828-pics-my-rt-10-rebuild-saga.html
Viper Scot
Viper Owner
Yes, the car had a front end accident Oct 2007 and I was thinking the impact might have caused some damage to the fairly fragile cat core. I'm not sure why a new map might cause this though (I've only gone for an SCT conservative re-map of the standard ECU)?? I never fitted the cats - the guy I bought them from did. For reference, in the pic, the widest dimension of the latice cross-section is 35mm.
Viper Scot
Viper Owner
Jon - they ABSOLUTELY did come out of the exhaust like that! Found that piece and a smaller one on my drive. I'm not 100% sure that they are RT cats but that's what I was told was in my car when I bought it 5 years ago. I've got no reason for telling tales about this - my initial post was just for interest!
Green Viper
Enthusiast
I had a battery go down, PCM struggled with either crank or cam sensor signal (can't recall which) when trying to crank over, it then dumped gas on extremely hot cats, misfired and shot flaming pieces (albeit smaller) out my exhaust, that was at Chelsea proving grounds during VOI-10. There are lots of witnesses, it was a random tech but the cheaper version.
SRT advised not driving or even starting the car, pulling the plugs and checking that no parts got sucked into the cylinders through scavenging. Mine may have been different since it basically exploded but you may want to check.
I also tried running no cats, throttle response was better but I lost 15 hp with the stock PCM and 45 hp with the hi-flow cat tune and it smelled aweful when at the stop lights, for me a new set of cats was the right move.
Good luck to you whatever you decide.
SRT advised not driving or even starting the car, pulling the plugs and checking that no parts got sucked into the cylinders through scavenging. Mine may have been different since it basically exploded but you may want to check.
I also tried running no cats, throttle response was better but I lost 15 hp with the stock PCM and 45 hp with the hi-flow cat tune and it smelled aweful when at the stop lights, for me a new set of cats was the right move.
Good luck to you whatever you decide.
Thanks for the follow-up. We sold those cats in 2001 to the prior owner. How many miles on the car now? 9 years in the car, 3 yrs post-accident.....5800 miles on car when new.
The enlarged photo makes it look like a BIG piece, but the honeycomb is much smaller in 1-1 photo, than in the photo shown. 35mm = 1.37 inches, which could indeed puke out of a 3" cat and exhaust. It sure would have rattled a LOT on its journey!
Viper Scot
Viper Owner
There's just over 25,000 miles on the car now. I'm presuming that the piece would have moved throught the exhaust under greatest load which might have meant that I wouldn't have heard anything due to the very high background noise under high revs?
But I still can't get a consensus of opinion as to whether it's OK to drive the car or not right now (with at least one collapsed cat). A very well respected tuner has said it'll be fine but others on this thread have said not to even start the car!
96RT......I dont like the uneven back-pressure, not a HUGE factor for short distances; GUT the other one, or replace them ..... They survived 9 years, 20K miles, and a frontal accident!
You could drive it that way, but it's recommended to removed the cats and make certain that the exhuast is clean. If any tiny pieces bet sucked into the engine they WILL be very expensive. Agreed that it's "not likely" so it you can afford to take a chance ... but you've been warned.
dave6666
Enthusiast
If you decide to gut the cat, I have some recipes I've been wanting to try.
Re: Exhaust Fractured
Random Tech engineer reviewed the photo, herewith his reply:
Jon-
>
> Judging by the condition of the substrate in the photo, it appears that
> this failure is the result of either physical impact or fuel "washdown".
> There's no evidence of overheating, so the failure had to result from the
> substrate fracturing. Obviously, if the converter was impacted, the ceramic core
> could crack and with time, the crack would grow longer and larger.
> Ultimately, a piece would break off and it, along with the remaining piece or
> pieces of substrate would no longer be held in place.
>
> The second scenario is that an excess amount of fuel entered the exhaust
> system, most likely after the engine had been turned off. This fuel would
> then permeate the mat that locks the substrate in place. When the engine was
> subsequently started, the fuel would burn and ultimately burn away the mat.
> With nothing left to hold the substrate in place, it would bounce around,
> fracture and the pieces could exit through the muffler.
>
> Either scenario could have occurred several months, or even years ago, a hairline crack takes time, depending on the number of miles driven since it occurred.
Random Tech engineer reviewed the photo, herewith his reply:
Jon-
>
> Judging by the condition of the substrate in the photo, it appears that
> this failure is the result of either physical impact or fuel "washdown".
> There's no evidence of overheating, so the failure had to result from the
> substrate fracturing. Obviously, if the converter was impacted, the ceramic core
> could crack and with time, the crack would grow longer and larger.
> Ultimately, a piece would break off and it, along with the remaining piece or
> pieces of substrate would no longer be held in place.
>
> The second scenario is that an excess amount of fuel entered the exhaust
> system, most likely after the engine had been turned off. This fuel would
> then permeate the mat that locks the substrate in place. When the engine was
> subsequently started, the fuel would burn and ultimately burn away the mat.
> With nothing left to hold the substrate in place, it would bounce around,
> fracture and the pieces could exit through the muffler.
>
> Either scenario could have occurred several months, or even years ago, a hairline crack takes time, depending on the number of miles driven since it occurred.
