Decat Potential Problems...

[Ste King 182]

Went to get a quote of my local exhaust center today to fit my jansped cat back with a decat on my 2005 182 and he went on quite alot about how much it can basicaly f**k your car up running a decat, he said it will bring emitions lights on, possibly put the car on limp mode, probs would have to have it remaped, etc, etc is he talking sence n should i leave the standard cat on? How many people have found problems like this with fitting a decat ? The last thing i wanna do is put my car on what he called limp mode lol ... Thanks alot ste.

 

[freemo77]

I like the idea of a de cat, nice and rapsy but does have following problems

Possibly too loud?
Have to change it over once a year, for MOT, not much of an issue but if you havent got easy access to the underside of your car, it can be a pain
Technically Illegal, not a road worthy car

But then again plenty of people do it, so its got to have some advantages

Not sure on f*cking up the car though, never heard anything about this, although it will put on your engine management light

 

[Ste King 182]

I like the idea of a de cat, nice and rapsy but does have following problems

Possibly too loud?
Have to change it over once a year, for MOT, not much of an issue but if you havent got easy access to the underside of your car, it can be a pain
Technically Illegal, not a road worthy car

But then again plenty of people do it, so its got to have some advantages

Not sure on f*cking up the car though, never heard anything about this, although it will put on your engine management light

yeh the lad said because its all electronics it will put the engine light on and this could put it in limp mode ?!

 

[syko6288]

get a obd reader from ebay or k-tec and just turn the light of as and when its on

i had de-cat on mine the light came on a month or two after fitting then once swithced it of it didnt come back on

 

[LowLife.]

Would people really do it if it put the car into limp mode? Find a different garage imo.

 

[hipwell]

He's chatting crap mate.

Itl bring the light on but won't affect how the car runs.

 

[Fletcher]

I've never heard a de-cat too put a 1*2 into limp mode..

 

[Kam.]

It can and does on many cars. The simple solution is to disconnect the second lambda from the exhaust and let it detect clean air.

 

[Ste King 182]

Is it better of getin a sports cat? avoid all these problems wont be as loud and wil pass mots lol !?

 

[hipwell]

there are no problems with a decat apart from a light on the dash which does nothing lol, and the fact mot and police wont like it.

 

[Arney]

dont disconnect the lamba sensor then the car will things something's wrong and probably f**k up the fueling.. just put it on and deal with the light.. never heard of any 182 going into limp mode due to a decat.. my 05 plate 182 has a decat on it.. 1 month in and the light came on.. 3 months later still drives as good.. sounds great... and F**K loads of fun!!

 

[hipwell]

The lambda doesn't need to be plugged in, the one in the cat has nothing to do with fueling, all it does is reports the data back.

I ran mine for 3 months without a second lambda plugged in.

 

[nick.]

Is it better of getin a sports cat? avoid all these problems wont be as loud and wil pass mots lol !?

I think i have read before that the cat on 182's is very close to the sport cats you can get with cell count, think thats the right phrase.
Plus de-cat pipe are a lot cheaper and if you don't like it ain't to difficult to sell on

 

[Mark One]

Having done a decat on a 172Ph2....
- Never heard of any cars in limp mode.
- The emissions light might come on imediately or never or it might come on after a few thousand miles.
- You can run with the downstream lambda unplugged, or even not screwed into the exhaust. This will not always solve the emissions light
- Keep your cat for MOT time
- If it's a 172 manifold, it's a little b*****d to fit.

 

[Gt rob]

put a de-cat on mine and never ever had any problems with it, just have to put original cat on once a year for mot. oh, i also fit exhaust for a living, n all the de-cats ive fitted havnt caused any harm.

 

[Scoop26]

Will the emmissions light go off again immeadiately when you re-fit the original cat (for the MOT)

 

[Bob the Frog]

I'm running a Decat on my 172. The Lambda Light came on after a while, and even after turning it off with an OBD reader it carried on coming back on.

However... as has already been said, disconnecting the second lambda sensor fixes that. All the second lambda does is check that the Cat is working properly - disconnecting it won't feck up the fuelling.

And the bloke at the exhaust center who said you'd balls up the engine was talking shite. Don't go there again: he's clearly clueless - either that or worried he'd loose business because he doesn't sell DeCats.... in which case, don't go there again.

 

[sammyhale22]

The rear Lambda sensor simply compares monoxide and co2 levels against the front lambda sensor. If it detects a high level i.e. the cat isn`t doing its job... then the emissions light will come on as a warning that the cat needs replacing. So if you disconnect rear Lambda sensor then that sensor will be picking up good natural air so the light will never come on! But they are only measuring devices, the only sensor that is essential is the front lambda sensor which is used for fuel mixture adjustment by the ECU.

 

[Yellow Dave]

my de-cat brings the engine management light on quite regularly, mainly when driving economically lol. turn it off and a few days / week later it'll be back on. As said the 2nd lambda only measures the CAT's efficiency and cannot effect the fueling, and it puts up a code to say it's below a set efficiency rating. Also it has made the exhaust quite a bit louder.

Mine has also reduced my MPG slightly where as others have claimed theirs have improved?

 

[hipwell]

My mpg improved, went from 42 to 45 on motorway, god knows why I put cat back on with these petrol prices lol