Problem with decat/magnex still..........

[jpmad4it2]

Im still having problems with my janspeed decat/magnex system..........im not really sure which one is causing the problem.

I thought the power draining problem was just due to the car running cold / emissions level problem (the common clio 172 / cup problem), but its been occuring randomly even when the car is WARM. Does this sound like a decat problem or could it be the magnex system thats the problem?

The guy at the garage who fitted it all thinks that i should have both lamba connectors plugged in, as the computer will be messed up otherwise. At the moment the first (pre) lamba connector is plugged in, but the second lamba sensor (post) is unplugged from the decat, yet it is left attached to the car and therefore the emissions light is plugged in.

Anyone got any suggestions? Anyone had this problem too?

J

 

[BenR]

try putting the second lambda in, definate fueling problem.

Cant give an answer from behind a computer sadly, need to see it.

 

[Hippychick]

try unplugging the second one from the loom

only problem is once the light is on the ECU stores a fault in its memory, and needs to be reset

 

[theduck]

sounds very similar to the problem I had with my decat, was down to lack of back pressure, in the end had to put my cat back on.

 

[jpmad4it2]

Quote: Originally posted by BenR on 12 July 2005


try putting the second lambda in, definate fueling problem.

Cant give an answer from behind a computer sadly, need to see it.

where are you based? I thought plugging the second sensor in can cause errors to be stored in the ECU?

 

[jpmad4it2]

Quote: Originally posted by Hippychick on 12 July 2005


try unplugging the second one from the loom

only problem is once the light is on the ECU stores a fault in its memory, and needs to be reset

you mean take the second sensor fully from the car?

at the moment the second sensor is tied up under the car(still attached to the car)

 

[jpmad4it2]

Quote: Originally posted by theduckeatspork on 12 July 2005

sounds very similar to the problem I had with my decat, was down to lack of back pressure, in the end had to put my cat back on.

sounds similar - the car will be drained of power no matter how much i put my foot down - if i keep my foot down the exhaust jitters and splutters and then all of a sudden the power kicks back in and you can hear the gases being blown outta the exhaust again. It usually happens if i put my foot down before 3000 revs - when it hits 3000 revs it just cant seem to get past that point.

 

[StevieP]

I think you need to have this looked at properly, I cant see a de-cat pipe causing problems like this?..? Then again I cant see the Magnex doing anything wrong either, maybe its an ECU or another fault.

Plug the second one in, there is a hole in the de-cat pipe as well remember where the sensor would normally be plugged in, have you had that sealed up as that will be blowing out a tiny bit if not. Dont think that would make much difference thou thinking about it.

 

[mixpioneer]

You cant just unplug lambda sensors, it will completely mess up your fueling.

 

[jpmad4it2]

Quote: Originally posted by StevieP on 12 July 2005


I think you need to have this looked at properly, I cant see a de-cat pipe causing problems like this?..? Then again I cant see the Magnex doing anything wrong either, maybe its an ECU or another fault.

Plug the second one in, there is a hole in the de-cat pipe as well remember where the sensor would normally be plugged in, have you had that sealed up as that will be blowing out a tiny bit if not. Dont think that would make much difference thou thinking about it.





well the car was fine before i had the magnex and decat put on.

I do have the second lamba sensor hole blocked up.

 

[jpmad4it2]

Quote: Originally posted by mixpioneer on 12 July 2005

You cant just unplug lambda sensors, it will completely mess up your fueling.

im gathering that a lot of peoples opinions differ - some say its fine to unplug the sensor whilst others think i cant - think i might try with it plugged in for a while and see how i go???? CAn anyone think of a reason why i shouldnt do this?

 

[Dootchy]

Ive got a custom removable Decat with both Lambdas in place, as well as a very loud custom system behind it, single box jobby- and no issues over back pressure/loss of power etc. Sounds very like ECU problem. Stick a tube up its erse & check the emissions first, most garages will have the machine to do it, especially if they do MOTs. Even accounting for the Decat, they;ll be able to tell you if the mixture is out at say idle & 3000rpm. Try using emmissions numbers for a similar capacity car, with similar compression ratio from before jan 1993- they should have a chart in MOT shops etc.

 

[jpmad4it2]

i dont need to do that - you can smell the emissions badly - its kickin out a lot of something anyway - a very strong gas smell

 

[theduck]

thats due to your decat, you need your 2nd lambda sensor plugged in, but by the sounds of it, it will still be doing that with it plugged in, therefore need custom map that takes into account your mods, that equals lots of moolah

 

[jpmad4it2]

who does custom mapping? How much will i be looking at for a remap with an ITG maxogen, janspeed decat and a magnex cat-back system ?


anyone in the north west area fancy having a look for me?

 

[Jonesy]

Have you tried resetting the ecu, i read some1 saying you need to disconnect the battery for about half an hour. Also you got these problems when you put on the decat and ik, why not put the old airbox back on, see if it makes any difference.

 

[McBunny]

right the second sensor is there for checking the emmisions at startup


you dont want it connected to the car at all mine was great for like 6k

 

[jpmad4it2]

Quote: Originally posted by Jonesy on 14 July 2005

<SCRIPT language=javascript> Have you tried resetting the ecu, i read some1 saying you need to disconnect the battery for about half an hour. Also you got these problems when you put on the decat and ik, why not put the old airbox back on, see if it makes any difference.

i had the magnex and decat on for a week before i had the induction kit on. Therefore its nothing to do with the induction kit. Are you sure its as easy as unplugging the battery to reset the ECU?

 

[jpmad4it2]

Quote: Originally posted by McBunny on 14 July 2005

right the second sensor is there for checking the emmisions at startup


you dont want it connected to the car at all mine was great for like 6k

does that mean cutting the sensor off? i had a look under and its attached by an electrical wire isnt it? Or does it unscrew from the car?

 

[Jonesy]

Dont take my word for it, i read it on here but that was for a valver, not sure if it applies to the 172.

 

[jpmad4it2]

its worth a try i guess

 

[jpmad4it2]

im getting 39MPG now whereas i used to get 33 before?

 

[GarethM]

is the problem fixed or is the 39mpg because of the power drain?

 

[jpmad4it2]

no its not fixed yet. I noticed that when i first start it up the revs when idle are low too - and the car starts shuddering.

f**k knows whats gonig on!!

im gonna uplug the battery tonight for an hour, give it a whirl and then put the second lamba sensor in tomorrow if things are still not right

 

[jpmad4it2]

resetting the ECU made no difference.

The bloody mechanic who blocked the hole up on the decat has welded a plug into it, so i cant get it off to fit the sensor.

 

[jpmad4it2]

keep getting a MPG reading of 99.9!!!!!!

 

[Mike@Rentech]

I dont think a de-cat and having the rear 02 sensor disconnected would cause the problems you have, i recon you have a fault on the injection system to cause the problems you are having.

which warning light are you getting come on, the one in the centre of the display or the one at the side, if its the one in the centre of your display that would indicate an injection system fault, the light to the side is just to let you know that there is a small fault and the emissions are to high hence why most de-catted clios have this light come on, running is not normally affected with the emission light on.

 

[Trueblue]

you need to have the 2nd sensor installed, the 2nd sensor is there to reassure the ECU that the 1st sensor is doing its job, i.e correcting the mixture at start-up...

so i take it, if you dont have the 2nd sensor in then the ecu doesnt know whats going on...

you need to plug it in somehow mate, take it to your local custom exhaust makers and get them to use their plasma cutter to put a hole in the decat, to enable fitting of the 2nd lambda...

hope this helps