3.9 V8 exhaust

thought i would post this here all suggestions welcome.

Ok so here it is i want to put a PHat stainless exhaust on my disco and tubular manifolds.

i dont have a clue where would be best to buy one can i get an off the shelf complete system from somewhere or will i have to get one custom made i quite like the look of twin exit.

also the lambda sensors........emissions are not an issue for my MOT i understand i need to change the tune select resistor if i bin them but i dont really understand what they are all for so if someone can enlighten me as to what they do etc and tell me what are the pro's and cons of keeping them or binning them

Many thanks everyone for your time and answersop2:

Hi Mate,
If you look in any Land Rover mag you will find custom exhaust ad'sOr look in yellow pages/google, for your nearest powerflow dealer who will make a system for you.
You could have a boss welded into the new manifolds for a lambda sensor so you dont have to mess with anything..


steve

thanks steve that seems like a starting point at least.
i know i can weld bosses in for the lambdas but what do i gain if i keep or bin them

With the sensors still in it will still take normal readings, so no need to change anything else.

steve

Lambas are needed to keep your ecu happy, the lambda Is mounted b4 a cat so if you ended up decatting you wouldn't have to remove them/ gain anything from removing them

would the ecu not be just as happy with a pre 94 uk spec tune select resistor or a gulf state one the 3.9 was just as happy before the cats were put on.
i cant find the thread to quote but i read that getting rid of the lambda sensors can help stop the liners slipping when running LPG am i miss guided?

Yes extreamly. Bin the cats keep the lambda sensors (HEGO's).

The reason some engines have problems with head gaskets and or cylinder liners is because the combustion chambers run quite a bit hotter when on gas.

I would keep the lambdas, as I understand it, the ECU has better control of the fuelling as the ECU is not using fixed point fuel mapping as it does when you use non-cat tune. I think it might be argued the lambdas make the engine a bit more efficient adn perhaps it might also be argued that if you carry a non-cat tune select resistor in the car as a back up, if your lambda sensors fail you can plug in the resistor so the ecu ignores lamda and hopefully gets you to where you need to go (in theory!)

thanks for everything everyone in the end i managed to get a nice falcon system including headers from rimmer brothers. i kept the lambda sensors. if i had known what a pig fitting the system was going to be i might not of bothered however 50mph through to 70 is much better and the engine spins up loads quicker without the cats. thanks again for all your advice

my 83 rr with a 93 4.2 lse engine in has no cat and the lamba sensors have just had the wires snipped off so dunno what mine is doin

biggen said:

thanks for everything everyone in the end i managed to get a nice falcon system including headers from rimmer brothers. i kept the lambda sensors. if i had known what a pig fitting the system was going to be i might not of bothered however 50mph through to 70 is much better and the engine spins up loads quicker without the cats. thanks again for all your advice

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video!!