Alright, heres the story. dad went and got a Nissan stagea RB25DET
after a day or two we noticed that clicking sound you get from a leaking exhaust manifold. now because it look like a real shit of a job we took it to the shop and dad just likes to drink piss all weekend and not work on cars
but anyway we took it to the muffler shop and had the manifold replace and he asked them to cut out his catalytic converter out, now from what i gather this is bad because the ECU thinks the engine is always cold and burns shit tons of gas and wreaks your bore due to bore wash.
So is this true? cutting your cat out is bad or does has no effect on your cars engine. I'v been surfing the net but all I can find and is forums full of old yanks complaining about smells and pollution
There are no issues. Cat, complete or gutted or no cat at all.
Apart from legal issues. And the "test" for a missing cat is remarkably simple. In fact ANY officer of the law or registration authority is qualified. Its a simple matter of just getting down on his hands and knees and simply LOOK!
No cat there where its supposed to by by law and a whole new world of money worries are your friend.
Cats have nothing to do with fuel mixtures. Whats this borewashing tripe?
L8r
E
Forcd4 wrote:Oh fuk no dude it's you a again, the oracle.
Bore wash as was described to me as an extreme overfueling issue where excessive fuel is pushed past the rings and causes damage to the bore ultimately filling the sump, never seen it only heard, sounds bad.
They would have had to played with something else for it to over fuel, run diagnostics and see first.
Im going to have to look and see if it had a sensor on the cat because I know that on some cars if your remove you cat the ECU thinks the engine is always cold and then stuck on cold start mode
and yes bore wash is very bad, ever had a car with manual choke and pulled it on so its sounds like a rotor? yeh dont do that basically there is liquid fuel running down the bore "washing" away the oil, no oil no lubrication
but if no one is sure what is going to happen algood, I get back to you next year and let you know if his car is guttless and buring heaps of oil
LOL! Oh I know what borewashing itself is but I want to know the theory behind the cat having something to do with cold running/enrichment.
The water temp sender is what instructs the engine as to whether its cold or not.
yep, some cats do have a sensor in them and Id suggest its a temp sensor but not for warming up.
Just let the ECU know that the cat is too cold to actually do anything and....and.... well buggered iffen i know but not to enrich fuel for cold running.
After all, cats warm to operating temps quite quickly, far quicker than the engine can.
L8r
E
Forcd4 wrote:Oh fuk no dude it's you a again, the oracle.
tassuperkart wrote:yep, some cats do have a sensor in them and Id suggest its a temp sensor but not for warming up.
Just let the ECU know that the cat is too cold to actually do anything and....and.... well buggered iffen i know
From Wikipedia
Wikipedia wrote:Temperature sensors
Temperature sensors are used for two purposes. The first is as a warning system, typically on two-way catalytic converters such as are still sometimes used on LPG forklifts. The function of the sensor is to warn of catalytic converter temperature above the safe limit of 750 °C (1,380 °F). More-recent catalytic-converter designs are not as susceptible to temperature damage and can withstand sustained temperatures of 900 °C (1,650 °F).[citation needed] Temperature sensors are also used to monitor catalyst functioning — usually two sensors will be fitted, with one before the catalyst and one after to monitor the temperature rise over the catalytic-converter core. For every one percent of CO in the exhaust gas stream, the exhaust gas temperature will rise by 100°C.[citation needed]
Oxygen sensors
The oxygen sensor is the basis of the closed-loop control system on a spark-ignited rich-burn engine; however, it is also used for diagnostics. In vehicles with OBD II, a second oxygen sensor is fitted after the catalytic converter to monitor the O2 levels. The on-board computer makes comparisons between the readings of the two sensors. If both sensors show the same output, the computer recognizes that the catalytic converter is either not functioning or has been removed, and will operate a "check engine" light and retard engine performance. Simple "oxygen sensor simulators" have been developed to circumvent this problem by simulating the change across the catalytic converter with plans and pre-assembled devices available on the internet, although these are not legal for on-road use.[22] Similar devices apply an offset to the sensor signals, allowing the engine to run a more fuel-economical lean burn that may, however, damage the engine or the catalytic converter.[23]
NOx sensors
NOx sensors are extremely expensive and are generally only used when a compression-ignition engine is fitted with a selective catalytic-reduction (SCR) converter, or a NOx absorber catalyst in a feedback system. When fitted to an SCR system, there may be one or two sensors. When one sensor is fitted it will be pre-catalyst; when two are fitted the second one will be post-catalyst. They are used for the same reasons and in the same manner as an oxygen sensor — the only difference is the substance being monitored.
So if this info is correct (Well as correct as wiki can be), I doubt that removal of a cat would lead to borewash,
thant for the input guys, within the next few weeks I will take it to tech with me and hook it up to the exhaust gas sensor thingy, and then find whats happening.
hi mate iv removed loads of cat converters if you have a warning light on the dash it is most likely because the exhaust shop removed the sensor that screws into the side of the cat, have a look adn see if its there if it is still there then it should be tack welded to the side of the pipe so the sensor remains earthed otherwise the cat light will turn on, if you have and engine check light on then you have most likely logged a code saying that the front and rear o2 sensors are reading the same values (that is if you have 2) which the ecu will recognise and may say that the sensors are buggered or that you have a cat converter fault.
