Pre cat removal Lambdas in or out ?

[Pasco]

Right the pre-cats are out i have a chip to go in the ecu and a Green tune resistor.Plus a Y pipe ACT cat replacement jobby.

The question my friends is do i put the Lambdas back in to act as a bung or do i plug the hole up with a bolt?
If so what size bolt, diameter wise, and what is the pitch of thread?

It looks M18 unf or something close.

Thanks as ever guys

Pasco

Edited by Pasco on Sunday 10th December 17:16

Edited by Pasco on Sunday 10th December 17:18

[dnb]

It's a fine metric thread so tricky to find bolts... If the green tune resistor still allows the power to the lambda sensors' internal heaters then I'd use them to bung the holes up and not worry about things. I don't think the green resistor takes any notice of lambda reading, but it's been a while since I had anything to do with the Lucas ECU stuff. (My griff run closed loop without cats, but many people consider me slightly odd )

[Pasco]

Hi Dave how are you

Interesting that.... will have to see what others think but would be the easy way for me

Still got the Chav motor?

Paul

[dmax]

Pasco said:

Right the pre-cats are out i have a chip to go in the ecu and a Green tune resistor.Plus a Y pipe ACT cat replacement jobby.

Edited by Pasco on Sunday 10th December 17:16

Edited by Pasco on Sunday 10th December 17:18

What is the Ecu chip you are taking about? is just the green tune resistor not enough normally?

Xavier.

[pupp]

I left my lambdas in situ and functioning (ie on the original tune resistor)... only because I couldn't locate the bloody thing to change it. No running issues but then again I'm on a Tornado chip

[Pasco]

By de-catting totaly,it makes the mix leaner the chip increases the amount of fuel to compensate for this.

And should give one or two extra HP and i mean one or two.

Pasco

[dnb]

Yes, still got the chav motor. I'm not allowed to replace it with a Cerbera just yet

[Cider Andy]

If you can find replacement bolts to act as plugs, then fine. If not, it is also fine to use the lambda sensors as plugs. If you ever want to re-use them in the future, you'll need to make an ignition switched connection to their heater circuits. If you don't want to re-use them, leave them disconnected.

All this is assuming you go ahead and fit the green tune resistor.

[Pasco]

BLOODY HELL pre cats out, main cat out, green tune resistor and a fuel chip and a super sports exhaust equals

One very loud motor Looking forward to GG07 even more now

I am one happy chappy

Bring on the BRF you know who you are !!

[eliot]

from memory the thread is M12x1.25
get a couple of stainless bolts or sets from:
www.namrick.co.uk/browse.asp?PCID=9

[griffter]

I've seen a spark plug used as a lambda plug. Must have been the same thread. I'm sure you could saw off the portion above the hexagon to make it look neater (and prevent 'hilarious' comments at the Griff Growl).

[Pasco]

Took her out for a spin and left it over night in the Griff Room.

Went to re tighten up the bolts and was quite supprised that i could get around a quarter of a turn on each bolt, well baybe an eigth.

Out again last night and this morning poped a spanner onto a bolt and same again.

Will tighten them all tonight but just wonder how much more the gaskets will compress.

Can anyone tell me what torque value they should be set at subject to getting a tool to all of the bolts.
I can not reach the off side bulk head bottom two bolts without dropping the exhaust again will try to reach them again tonight.

What it does tell me is that there are quite a lot of Griffs and chims driving around with Man bolts not tight enough

[spend]

I think you are supposed to use lock washers. From memory they are not very highly torqued - but you can only do by hand anyway. I believe this is why the later LR twin steel gaskets have become popular BTW.

Dave

[lig]

Hi Pasco..

for what its worth.....I was running with a GTR for well over a year with the llamdas still in situ and at MOT time they worked fine. I have now fully decatted and still have them in situ and am expecting them to work fine again (at MOT time when i put in the main CAT)??

I still have them plugged in, I dont know if they still have power to them or not? Does anyone know??

I was under the impression that the GTR told the ECU that there was no cats and therefore no llamdas so the electric circuit to the llamdas was disabled, is this not the case?? Suppose i could always get my meter out to test!!??

Lig.

[Pasco]

Spend / Lig

I have split washers in place and will monitor the situation glad i built a pit in the Griff room.
Lig what you have said is correct but the heater circuit on the Lambs is disabled so they may fail in time if using,as i am, a GTR.

Cheers Guys