swrdply400mrelay
Well-Known Member
Did you get it fixed? Taking mine back tomorrow, the shop is going to check for leaks with smoke.
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Catted Downpipe Smell?
- Thread starter B58_ hwAyaq
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ethanc
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The second shop did catch a leak at least between mid pipe and downpipe, I feel like there might be one between downpipe and turbo as well. But need to get Toyota to replace/fix trans oil pan leak first, then I’ll go back and have the second shop redo the entire downpipe install. The foreman at my Toyota ordered the replacement oil pan, fingers crossed that that fixes it, the other threads make it seem like the issue is often something else. I bought new gasket, v band, and upgraded mid pipe/downpipe clamp for the reinstall.
Keep us posted on how the smoke test looks, my guess is at least a leak between mid pipe and downpipe, it seems the aa dp outlet can sometimes have some depth and girth issues when going into the mid pipe so might not be fully sealed. When I had the second shop check for leaks, it was immediately apparent. He even had me put my hand right by the connection and I could feel the obvious pulsing air coming out. The down pipe to turbo I’m unsure about, which is why I’m going with an entire reinstall with new hardware, at this second shop.
MoTeC_R
Well-Known Member
Sorry you guys are having these issues. Like I said, I have zero smell with the AA 4.5” Catted pipe, so if all is correct it should be very minimal worst case scenario.
On a side note that was also mentioned here-I paid to swap to the metal M3/M4 trans pan instead of dealing with headaches from repeated Toyota services of failed repair of the plastic pan set.
On a side note that was also mentioned here-I paid to swap to the metal M3/M4 trans pan instead of dealing with headaches from repeated Toyota services of failed repair of the plastic pan set.
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sircodemane
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Adding my own experience to this: I first switched from stock DP to VRSF catless and the smell was so much worse than I expected and the constant CEL did make me paranoid that I could be missing real issues. CTS Turbo had a big sale on high flow cats (200cell) so I switched to that and now I don't get CEL anymore (with stock ECU/tuning!) and the smell is not really noticeable anymore.
ethanc
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Has the metal trans pan prevented future leaks? Or any leaks elsewhere?
MoTeC_R
Well-Known Member
So far so good and I believe everyone that has upgraded has had positive results after the upgrade. The M3/M4 pan is a little larger but still allows for you to keep the under-cladding in place. You could remove it but I prefer to keep it in place. I’d recommend it since I’ve not heard of any positive experiences with warranty thru Toyota.
swrdply400mrelay
Well-Known Member
Went back to the shop, and they couldn't find a leak. I'll just use the A mode only when I'm on the highway, and M mode city driving/stopped.
gr_supra_lt
Active Member
Hey. I had the same issue as soon as I switched to CEL200 sports downpipe. Exhaust gas smell coming thru interior vents and also unbearable smell in engine bay by turbo. We reinstalled downpipe 3 times, new DP to turbo gaskets, both new V-band clamps. Still the same. Until my guys noticed on one small corner DP to turbo connection 1mm open gap where exhaust gases where escaping. I sent back catted downpipe to manufacturer and they found out that flex part of downpipe was damaged and it ruined whole shape of downpipe so it didn’t sit correctly which made it leak. Damaged either by shipping or bad thermal break in period. I would suggest to change downpipe or send ir back to manufacturer. Driving with exhaust leak after turbo and before O2 sensor may kill your engine in long term due to O2 sensors detecting fake lean fuel situation where your DME will enrich the mixture and wash cylinder walls. Good luck!
swrdply400mrelay
Well-Known Member
I had another shop look at it, and they fixed it. First shop didn’t align correctly.
NocturnalEmber
Well-Known Member
The issue with catted downpipes is it becomes a pretty grey area due to the quality of the cat itself. Any car running an aftermarket catted downpipe has the ability to smell. That being said, all cats are also not created equal either.
Generally a higher cell count will clean the exhaust up more and tend to smell less. Of course smell is also subjective, so what one might consider minor another might consider potent, the ole olfactory senses at work.
The cat is going to be the most expensive piece in any catted downpipe in most scenarios. Based on cost/quality, I think I've heard quite a bit about Gesi and their cats regarding performance and smell. Of course the companies that use these tend to also sell the most expensive downpipes.
Generally a higher cell count will clean the exhaust up more and tend to smell less. Of course smell is also subjective, so what one might consider minor another might consider potent, the ole olfactory senses at work.
The cat is going to be the most expensive piece in any catted downpipe in most scenarios. Based on cost/quality, I think I've heard quite a bit about Gesi and their cats regarding performance and smell. Of course the companies that use these tend to also sell the most expensive downpipes.
gr_supra_lt
Active Member
Yes it depends a lot on type of cat being used. Personally I don’t care how it smells behind me, issue with guys here was that we had our downpipes leaking by turbo area and all those exhaust fumes were sucked into the cabin. And speaking about cats stock is CEL600-800 (density of comb). My Supra is Euro spec so it has basically two cats, another is OPF/GPF (gasoline particulate filter). My current aftermarket catted downpipe is CEL200 basically next step before catless. Catalytic converter on my DP is EURO6 grade which is basically current emissions regulation here in Europe and it smells almost like oem downpipe to be honest, on idle rpm and exhaust has day and night difference
NocturnalEmber
Well-Known Member
Yes it depends a lot on type of cat being used. Personally I don’t care how it smells behind me, issue with guys here was that we had our downpipes leaking by turbo area and all those exhaust fumes were sucked into the cabin. And speaking about cats stock is CEL600-800 (density of comb). My Supra is Euro spec so it has basically two cats, another is OPF/GPF (gasoline particulate filter). My current aftermarket catted downpipe is CEL200 basically next step before catless. Catalytic converter on my DP is EURO6 grade which is basically current emissions regulation here in Europe and it smells almost like oem downpipe to be honest, on idle rpm and exhaust has day and night difference
I imagine if its conforming to Euro6 then there's probably little to no smell at all.
As technology has advanced with cats, they are likely less and less of a restriction that they used to be. A high end cat will solve most issues if I had to guess.
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