Question about tune resistor??

Hello everybody,

I have a land rover 90 3.9.The engine had cats when i took it from a range rover but i removed them as they were too rusty.Though i kept the lamda sensors.The problem now is that i don't know which tune resistor should i use and where the MAF should be set at.Right now it has the white tune resistor.Any suggetions would be appreciated!

Thank you.

Anyone..???

I think as you removed the catalytic converters then you should change the tune resistor. Here is the list:

White 3900 Ohms - USA and European vehicles with catalytic converters
Green 470 Ohms - UK and European vehicles without catalytic converters
Yellow 910 Ohms - Saudi vehicles (without catalytic converters.)
Red 180 Ohms - Australia and "the rest of the world."

So change it for a 'green' tune resistor that has a resistance of 470 Ohms...



Are the lambda sensors are after the catalytic converters? So I think you could also remove these and just block the hole with the correct size bolt. Unsure on this last one, as when you change the tune resistor to non-cat then it will effectively ignore the lambda sensors perhaps? Might need some clarification on this last point.

Thank you for your response marccleave.

I've seen the tune resistor list at a previous post but don't know which one is the correct now.Surely if i put the green one,it will ignore the lamda sensors and it's not an option since i changed them last month with new.Also the lamba sensors are before the catalytic converters.Do you know what should be the MAF readings with the white tune resistor and what with the green?

Why do u wish to change the resistor, the ECU has the ability of readjusting the fuel map to some extent.
I replace my exhaust cat back system for a Janspeed system and just by doing the idle speed shot up to 3000rpm for around a minute then it settled down back to normal, all taken care of by the ECU.

Well,if it's not necessary i don't want to change anything.I just thought that since i removed the cats i need to change the fuel map also.That came to my mind because of the smelly exhaust....What about the air flow (MAF) setting?

If you look back in time your find stainless exhaust and people complaining of lack of apparent increase in power-look at tune resistor discussions

dimitris8390 said:

Well,if it's not necessary i don't want to change anything.I just thought that since i removed the cats i need to change the fuel map also.That came to my mind because of the smelly exhaust....What about the air flow (MAF) setting?

Click to expand...

I didn't know the the MAF had any user settings.
If the engine is running ok and the same with the emissions then leave alone.

No cats requires 470 ohm resistor. Ask a sparky to do a potentiometer set to 470 ohms that's what I did. You cannot buy them from anywhere

Stick with the White tune resistor for sure as if you change to the green one itwill stop your ECU looking at the Lambdas so you remove the ECU's ability to adjust its fuelling parameters.

470 ohm 0.5 watt rated and either 10 or 5% accuracy available to buy