Exhaust System...
- Thread starter Stani1029
- Start date
No, as far as I know you don't HAVE to have one - the cat-back and the manifold should go on just fine with the standard cat in place. However, you may wish to replace the cat with a janspeed one anyway, if you are going to do the rest of the system. The car will fail the MOT with the janspeed manifold on, so you may as well get rid of the 2nd cat also. Just make sure the standard system is on for MOT time!
Napster
And the Wide Green Bug
so is that correct!! that my micra will fail with janspeed manifold on and de-cat??
so if i but standard manifold back on and leave de-cat it should be ok?
what if i kept manifold on but but old cat back system on???
cheers
napster
Napster
And the Wide Green Bug
cheers arnold...i wish that was true because i got worried, as i read a few other threads (by searching
) and its the manifold that may be the problem,. but if so im stuck because the garage that added my manifold and exhasut.....DIDNT HAVE A CLUE HOW TO FIT and cut my manifold in half :-( and so havent got a standard manifold :-(can anyone else clear this up as to whether i just need "one CAT" and doesnt matter which one???
59 bhp is more than enough
Deactivated Account
i have a full janspeed exhaust for sale and manifold if your interested
I didnt pass the MOT with a janspeed manifold and secondary cat. However, i know some people have with this set up. Chances of passing seem to be increased by turning down the fueling with an SAFC, a PBV or anything else that can control fuel. The best thing to do i guess is to put it in for its MOT, then worry about it if it fails. The only way i could pass was to put the standard manifold back on.
this was for a CG13.
this was for a CG13.
Napster
And the Wide Green Bug
well im goin to have to put it in for MOT with janspeed manifold on because i dont have a STANDARD manifold :-( but i will but back on the standrad exhaust system with CAT?
if i fail what would i do?? is it best i try and get a standard manifold from a scrap yard 1st and if it fails say i have an original and get them to fit it?
so it will fail on emissions?? thats the only problem concerned with janspeed manifold???
thanks everyone your helping loads :laugh:
If you have to put it in for the MOT with the janspeed manifold on, then it is a good idea to have the rest of the system standard. As Ian says, if it fails with the janspeed manifold on then you can worry about it. Best (and pretty much only) thing to do if it fails would be to fit a standard manifold, just to get it through the MOT. Unless you fancy changing the fueling.
even if it fails the mot, this garage i take my car to will pass me to cut his work load...better than swapping it all to pass and then swapping it all back
For all you know, you could be driving a potential death trap, just cos he wants to cut his work load! He should be reported.
Alienfish360
Awesome Dawson
and it's illegal.
The only way he can do it, is to probe somebody elses car. As the results are recorded by computer as they are done for emissions and stored on VOSA database
You get pulled over for noise.....
Roadside emissions check.....
You Fail....
They check your documents, you get fined, they get fined, the garage you take it to gets their license to do MOT's taken off them.
You're left with a car with no MOT, and points
The only way he can do it, is to probe somebody elses car. As the results are recorded by computer as they are done for emissions and stored on VOSA database
You get pulled over for noise.....
Roadside emissions check.....
You Fail....
They check your documents, you get fined, they get fined, the garage you take it to gets their license to do MOT's taken off them.
You're left with a car with no MOT, and points
the garage would just say he must've fitted it after. they'll get away scott free.
if you get a second oil dipstick and cut it down to the handle (and keep your original one at home for checking oil level.), they can't do a road side emmissions test as they need to know the lenght of the dipstick for oil temp probe and also to make sure there's enough oil in engine so they don't damage engine during test.
Napster
And the Wide Green Bug
so let me get this right:
i know i should have CAT on my car because of its year, but if i get pulled over by the police and they check it, i will get points?
going back to MOT, its the emissions test im going to fail on and nothing else? should i then get a standard manifold and stick it in the car when it goes down? or just wait for a phone call and then take it down?
cheers guys, but im alittle worried now :-(
Napster
And the Wide Green Bug
so its emissions then? that does suck. i know it would fail without a CAT but not emissions.
quote "I didnt pass the MOT with a janspeed manifold and secondary cat. However, i know some people have with this set up. Chances of passing seem to be increased by turning down the fueling with an SAFC, a PBV or anything else that can control fuel"
so its todo with more "fuel"??? so with one of those "FSE power boost valves" can i adjust that nozzle to stop more fuel? or will i still fail.
thankyou
The standard cars are mapped a little on the rich side to keep the cats hot, so they do their job. When you remove the pre-cat it seems that the fuel is not fully burned off by the mid cat.
You can get around this using an adjustable fuel regulator on the standard ecu. It's an extra expense but way easier than removing and re-fitting the manifold each year.......plus if you have a janspeed they are prone to corroding, which makes removal very hard and if you damage a gasket, they are not cheap.
It's the down side of having a modified car on a standard ecu. I expect Pete, (for a fee), could find a better solution and adjust the ecu's settings.
You can get around this using an adjustable fuel regulator on the standard ecu. It's an extra expense but way easier than removing and re-fitting the manifold each year.......plus if you have a janspeed they are prone to corroding, which makes removal very hard and if you damage a gasket, they are not cheap.
It's the down side of having a modified car on a standard ecu. I expect Pete, (for a fee
), could find a better solution and adjust the ecu's settings.
Napster
And the Wide Green Bug
The standard cars are mapped a little on the rich side to keep the cats hot, so they do their job. When you remove the pre-cat it seems that the fuel is not fully burned off by the mid cat.
You can get around this using an adjustable fuel regulator on the standard ecu. It's an extra expense but way easier than removing and re-fitting the manifold each year.......plus if you have a janspeed they are prone to corroding, which makes removal very hard and if you damage a gasket, they are not cheap.
It's the down side of having a modified car on a standard ecu. I expect Pete, (for a fee
THANY YOU "LOW RIDER"!!!!!!
so will a "Power boost valve" be worth investing in because they can lower fuel? then i will just lower fuel into engine when MOT comes? any bad points from ristricting fuel? or all that would happen is car will stool with no fuel..correct?
i dont want to take manifold off...thats for sure and buying a standard one seems alot of work :-(
to some up....if i put standard exhaust on, leave manifold as it is, but adjust fueling, i should pass MOT Emissions!!!???
hopefully "micra pete" can shed more light...because hes been working with the ECU for a while now hasnt he / havent u??
cheers
There are better options than the PBV's as they can be unreliable. Ask Ed for some advice on an alernative. Bear in mind what Raceworx said......only lower the fuelling for the test, as soon as it's over set it back to where it was before, or you could risk engine damage under load.
Most come with a pressure guage fitted, so this is pretty easy. Stock fuel pressure should be 3bar, I find reducing this to around 2.6bar for the MOT seems to bring things in line.........best thing to do is get someone from a garage with an exhaust gas probe to monitor it as you adjust the regulator.
Most come with a pressure guage fitted, so this is pretty easy. Stock fuel pressure should be 3bar, I find reducing this to around 2.6bar for the MOT seems to bring things in line.........best thing to do is get someone from a garage with an exhaust gas probe to monitor it as you adjust the regulator.
Alienfish360
Awesome Dawson
Also if you're slightly too lean you will still fail on emissions as your CO2 will be too high.
Best thing to do is put your standard manifold back on for the test.
CO2?!? That's not quite right......If the car is too lean you'll pass on CO and HC but Lambda could be too high and go outside the spec limits.
MOT specifications measure CO, which has to be less than 0.3%. HC which has to be less than 200ppm and Lambda which has to be between 0.97 and 1.03. Technically you can have as much CO2 as you like, afterall that's what the cats job is to do
MOT specifications measure CO, which has to be less than 0.3%. HC which has to be less than 200ppm and Lambda which has to be between 0.97 and 1.03. Technically you can have as much CO2 as you like, afterall that's what the cats job is to do
The cat next to the manifold is the one that heats up first and is there to reduce the emissions from start up. The one under the car should be enough to get the car through the mot providing it is nice and hot. This works best if you can give the car a good run immediately before the test. If you leave the car at a garage all day, and they fire it up at 4pm and put it staight on the rig, it will struggle to meet the emissions limits.
Alienfish360
Awesome Dawson
After a brief discussion regarding this with Ed. His belief as I understood it is that the lambda does not see enough of the gasses to accurately adjust the fuelling therefore has issues at MOT time.
However, I'm sure Ed may at some point elaborate further on this, as he has a far better understand of it than myself.
However, I'm sure Ed may at some point elaborate further on this, as he has a far better understand of it than myself.
59 bhp is more than enough
Deactivated Account
whats this got to do with price of bacon?
yeah the lambda only really makes a difference at light loads and idle, the rest of the time its an open loop system. But again what has this got to do with anything?
Napster
And the Wide Green Bug
THANKS EVERYONE, IM FEELING ALITTLE BETTER
right so here is the plan:
i will get a standard manifold from scrap yard.
then when MOT comes i will add standard exhaust system, but leave janspeed manifold on.
i will take car down WITH standard manifold in the boot
if it fails i will ask them to fit olf manifold
?????????????????
is that a plan or not??
i really dont want to keep changing manifolds ever year for MOT :-( ?
do you think its worth taking it to a garage and get them to check the emissions BEFORE it goes in for test? or are they not allowed to do that?
napster
right so here is the plan:
i will get a standard manifold from scrap yard.
then when MOT comes i will add standard exhaust system, but leave janspeed manifold on.
i will take car down WITH standard manifold in the boot
if it fails i will ask them to fit olf manifold
?????????????????
is that a plan or not??
i really dont want to keep changing manifolds ever year for MOT :-( ?
do you think its worth taking it to a garage and get them to check the emissions BEFORE it goes in for test? or are they not allowed to do that?
napster
Personally I wouldn't trust anyone with my car, especially not my manifold but then mine is a one piece unit, which requires the alternator to be removed to fit it hehe.
I'm sure they would also charge you for this service.......it would be much better to have a sensible work around rather than doing a removal and re-fit each year.
In regards to the lambda sensor not seeing enough of the gasses, this is true. The sensor only sees gasses from 2 cylinders, as opposed to all 4 on the standard system, so this will effect what is being fed back to the ecu.
I'm sure they would also charge you for this service.......it would be much better to have a sensible work around rather than doing a removal and re-fit each year.
In regards to the lambda sensor not seeing enough of the gasses, this is true. The sensor only sees gasses from 2 cylinders, as opposed to all 4 on the standard system, so this will effect what is being fed back to the ecu.
Napster
And the Wide Green Bug
confused again :-(.......sorry
whad did you mean by your second paragraph?? about "work round"?
you think i should leave manifold on all together (i would prefer that) but then i add old exhaust system and get a fuel regulator and adjust it just for MOT???
but with out checking with a garage that the emissons r ok before hand..it would be a waste of money buying it cause the garage cause still fail me.........AND THEN.......they may not change fuel right, but get me to take manifold off :-(
