Tuning Catalytic converter

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Tuning Catalytic converter

Wills_1990

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Sorry about last post was getting confused after talking to a mate and ended up talking rubbish haha, what i wanted to know was does it have any effect on the the car with warning lights etc. if you remove the catalytic converter out of the exhaust and put in a decat pipe, i have heard on newer cars it can cause problems with warning lights but im not sure if this is true, if anyone has done it can they let me know if it was worth it or not? cheers(y)
 
does it fail mot even on the 1.9 mjet as i thought with the diesel you were able to take the cat out without any probs with mot??
 
does it fail mot even on the 1.9 mjet as i thought with the diesel you were able to take the cat out without any probs with mot??

Donn't have experiance with the fiat engine, but cat can be removed on VAG 1.9's and they have no probs with the MOT, and the fiat engine is newer and cleaner than the 1.9 VAG, so I assume no probs except for warning lights...
 
I've also heard that the JTDm can run without the cat, however not sure what any post cat air quality/oxygen sensors will make of this and weather the fueling will be adjusted in an attempt to lower the new emissions its reading.

is the MOT fail for the absence of the cat rather than the emissions being outside whats allowed?
 
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I've also heard that the JTDm can run without the cat, however not sure what any post cat air quality/oxygen sensors will make of this and weather the fueling will be adjusted in an attempt to lower the new emissions its reading.

is the MOT fail for the absence of the cat rather than the emissions being outside whats allowed?

as far as I know they don't even check emissions, just a smoke test.... I could be wrong, I'm sure some mechanic guy will set me right ;)
 
Yeah, just reading up on it now.

The exhaust system will fail the MOT if:

* Part of the system missing or excessively deteriorated
* A mounting is missing or damaged so it does not support the system
* There is a major leak
* The system is excessively noisy.

Its whether or not the missing cat counts as a missing part of the exhaust or if thats refering to a physical gap.

or theres this -http://www.imoc.co.uk/forums/viewtopic.php?t=43072
One important issue must be cleared up straight away. There is no requirement for a catalytic converter to be fitted to any vehicle, regardless of its age. It is however the most popular way of ensuring engines meet the emission legislation. The MOT test is testing the emissions from the tailpipe and if those emissions meet the standard then the vehicle passes. The term 'cat' test is inappropriate, the correct term is 'advanced emission test'. Its not the 'cat' that's being tested. There are a number of vehicles which are subject to the 'advanced emission test' but are capable of meeting the requirements without the use of a catalytic converter.
 
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well a mate of mine has a 306 2ltr hdi and he has had the cat removed or particle filter in a diesel and has had no problems with the mot, but with the mjet being a lot newer i thought there would probably be some sort of warning light that comes up but im sure i can get it sorted by someone, also has anyone ever removed the egr valve cus this mate of mine has also removed this and filled in the hole and now has a cleaner running car aswell as it revving more freely? :S but i dont know what this will do on a newer car

cheers
 
Warning light will flash up and stay on if you remove the cat. Just leave it on pointless changing it if you havent done anything else.

agreed, I'd just put up with the light....

do a search for "swirl gasket" for the EGR, when I had my EGR replaced (at about 70k) it would always hesitate on slight throttle when warming up (like the "stutter" in the BLT engined fabia vRS) I had the swirl gasket put in at the last service with the cambelt (90k) and it has cured it completley with no warning lights... (y)
 
Are we talking about the mjet pre-cat or the particulate filter? Removing the former would likely lead to the DPF clogging more regularily (if fitted) with early oil degradation, removing the latter would cause various faults to be recorded regarding the pressure sensor.

Bear in mind that Citroen and Peugoet use a different system for DPF.

EGR removal/blanking will cause combustion chamber temperatures to rise with possible increased chances of engine failure.
 
Are we talking about the mjet pre-cat or the particulate filter? Removing the former would likely lead to the DPF clogging more regularily (if fitted) with early oil degradation, removing the latter would cause various faults to be recorded regarding the pressure sensor.

Bear in mind that Citroen and Peugoet use a different system for DPF.

EGR removal/blanking will cause combustion chamber temperatures to rise with possible increased chances of engine failure.


Turbo failure too as those hot gasses gotta go somewhere :), the two O2 sensor readings being the same may upset the ECU & Fuelling though and thats what you've really gotta find out if you remove the CAT
 
Usually only the latest Euro5-spec DPF mjets have a lambda sensor and it's purpose is purely to check the airflow meter readings match the targets in the ECU. It's not as involved as a petrol engine's pre- and post-lambda setup.

Looking on Elearn, it shows 1.9 non-DPF mjets have a lambda sensor.
 
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