Help needed after fitting 4 2 1

18th July 2010, 15:49

hi i fitted a 4 2 1 raceland manifold yday to my mk 2 vtr the cat is on the downpipe, i found it a real pig to relocate the oil filter as i couldnt tap the oil return hole properly lol but managed to do that anyway and then it was really hard to put the manifold on but i cant work out which lamba has to go into the mani? i put the bottom lamba into the bottom of the mani and the top one tha goes into the mani i left unplugged! is this rightt? also since fitting the mani my car is going worse tbh it feels flat through gears

18th July 2010, 15:50

lol, no other way round.

18th July 2010, 15:58

ye wrong way round mate. first one goes in as thats the one that decides wether the car is running too rich or lean etc and corrects it. second only rely there to tell you when the cat's fucked. just swap them over and sleave the second one

18th July 2010, 16:06

is tha maybe the reason its running shitee?

18th July 2010, 16:08

Well your lambda is sniffin fresh air, when it should be sniffin the fumes in your exhaust..

So ye..lol

18th July 2010, 16:10

the top one i havent even plugged in mate the bottom one i have put in the bottom of the mani this is wrong yeah so i need to get the top lamba and put it in the bottom of tha main?

18th July 2010, 16:14

First one goes into your manifold

Think about it, that first one went into the manifold before the Cat, so it will be sensing the fumes before being cleaned.... keep it the same now, that same snsor needs to be in sensing the same air as before.

The second one, just tests the air is cleaner after the cat, making sure its doing its job. Obviously becouse you havnt got a cat anymore then having that sensor in will make the ECU think the cat is fked. So leave the second one in the fresh air and it will sense cleaner air making it think the cat is doing its job.

18th July 2010, 16:17

Quote:

Originally Posted by db_sax

First one goes into your manifold

Think about it, that first one went into the manifold before the Cat, so it will be sensing the fumes before being cleaned.... keep it the same now, that same snsor needs to be in sensing the same air as before.

The second one, just tests the air is cleaner after the cat, making sure its doing its job. Obviously becouse you havnt got a cat anymore then having that sensor in will make the ECU think the cat is fked. So leave the second one in the fresh air and it will sense cleaner air making it think the cat is doing its job.

ok mate thanks alot u have been a great help, what would this make my car run like though because atm it is horrid its slower than before i fitted the mani too

18th July 2010, 16:20

lol!

Its because of that sensor, just swap them back round.

The sensor you have left in the fresh air should be monitoring the Co2 in your exhaust. It adjusts to what its sensing and your fuel/air ratio change accordingly. As you left yours in the fresh air then its probably thinking theres not enough fuel going in and shootin too much in making it run way to rich and bogging down n making your car feel shit.

Just sort them sensors out.

18th July 2010, 16:21

Quote:

Originally Posted by db_sax

lol!

Its because of that sensor, just swap them back round.

The sensor you have left in the fresh air should be monitoring the Co2 in your exhaust. It adjusts to what its sensing and your fuel/air ratio change accordingly. As you left yours in the fresh air then its probably thinking theres not enough fuel going in and shootin too much in making it run way to rich and bogging down n making your car feel shit.

Just sort them sensors out.

ok mate does the bottom one have to be sleaved or can i just leave it unplugged?

18th July 2010, 16:23

Dont have to unplug it. Just keep it tied secure somewhere and in fresh air. You can get sleeves from either Kam Or GMC cant remember which now, alot of poeple shove them in bags

18th July 2010, 16:25

so basically just stop it from getting any shit air or dirt onit then?

18th July 2010, 16:26

Yarrr n getting cought on anything.