Temp test done on cat-

A

andysat

Lifer
Hi all-took to an indy(emission light on again) they did a temperature test along the length of the exhaust and found that its cooler after the cat than it should be,though it didnt log any faults-is this something that can be cured with an additive?-thanks
 
pvr said:
Is this after the cat was replaced by the dealer ????
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The stealer backtracked mate when i had it booked in,half an hour later i got a call saying it was a different cat to what they first thought!-so no cat fitted :roll:
 
Won't it be cooler, the further away from tneanifold naturally anyway!
The cat will take heat from the exhaust anyway and radiat it through the side walls of the housing.

What were they trying to prove?

When I worked on extremely large engines, the heat in each individual cylinder (when measured at the cylinder outlet) to determine the amount of fuel being injected to ensure that one cylinder was not doing more work and exerting more effort than the others on the crank.

I don't see what was being measured and what conclusion could be made.

Dario
 
Surly it can only be the same temperature coming out as coming in when the unit has reached thermodynamic stability. Ie that no further heat can be absorbed by the item it's passing through.

The cat will absorb heat, some heat will pass through, but some heat will be radiated through the matrix and ultimately radiated to the exterior casing.

It should take a fair while for this to achieve this in my opinion.

I still pose the question, what were they trying to determine?

If it was twin runs of exhaust, and one pipe was hotter than the other you could determine that that pipe has a reduction in flow causing great heat to be radiated to the exhaust pipe wall.

Dario
 
have you tried any fuel system additives yet ?
for all the hassle you have been through £12 must be worth a punt ? even if no fix it will help clean things up inside :wink:
 
mr wilks said:
have you tried any fuel system additives yet ?
for all the hassle you have been through £12 must be worth a punt ? even if no fix it will help clean things up inside :wink:
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Yeah you are right-its just that the stealer told me its a big no no-but then they would wouldnt they :roll:
 
andysat said:
mr wilks said:
have you tried any fuel system additives yet ?
for all the hassle you have been through £12 must be worth a punt ? even if no fix it will help clean things up inside :wink:
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Yeah you are right-its just that the stealer told me its a big no no-but then they would wouldnt they :roll:
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And have you given it a good thrashing yet?
 
the cat generates heat......I assume they can get a reading of its temperature from the oxygen sensor fitted just aft of the rear cat ?
 
slick said:
the cat generates heat......I assume they can get a reading of its temperature from the oxygen sensor fitted just aft of the rear cat ?
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The post cat sensor doesn't have enough wires for a temp function to be possible as I see it. The pre cat sensors have more wires, the potential may exist there.

I can see some logic of the temp change, there must be some "normal" range of temp change through the cat under normal conditions. Any significant variance indicates something amiss. What's amiss I'm not sure. Then again, I can imagine there being something amiss and yet the temp change is normal. So I'm not sure what it's telling us, but I guess I'll allow that it might tell us something. :?
 
If the stealer/2 indy's i have taken it to could guarantee 100%that fitting the cat would solve the light problem-i would have it done and move on-but as there was no fault code logged last time :roll:
 
Can you not get an agreement that if this doesn't fix it, they refund you the part (if not the labour). The cost is bloody ridiculous for some tech to be sticking a finger in the air and guessing.
 
Stuart Truman said:
Can you not get an agreement that if this doesn't fix it, they refund you the part (if not the labour). The cost is bloody ridiculous for some tech to be sticking a finger in the air and guessing.
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Agree-the stealers said if they fit the cat and the light comes on afterwards they would be at fault(how am i supposed to have faith in that statement?)
They said they would refund the cost of it -but they said the light could throw up a different fault code then-i can see where that ones going :roll:
As it never threw up a code last time the indy said who knows it may have been doing this since new :roll: -bit of a strange problem he said.
Tbh as they did a running laptop roadtest and they said all the values of everything was spot on and it would fly through an emissions test on the mot i am going to leave it and just enjoy the zed(money put aside for cat in future if the worse happens)
 
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