Welcome to EFI Extras website.

Parts and Accessories for your Engine Management Installation.





Spartan 2 with Bosch 4.9 LSU Lambda Sensor

Price: £130

Spartan 2 WideBand Lambda Controller and Bosch 4.9 Lambda Sensor - £130

Spartan 2 is the first Wideband Oxygen Controller to use all extended temperature components, this means Spartan 2 offers

the widest operating temperature; -40[C] to 125[C], of any Wideband Oxygen Controller on the market.

From the frozen Arctic Tundra to the baking heat of Death Valley, Spartan 2 is the Wideband

Oxygen Controller you can rely on.

See HERE for more details on this fantastic wideband setup.

For wiring info see HERE.

See HERE. for the instruction manual.


LS-2 Coil Near Plug (COP) Ignition Coil - No Driver Needed - Built in Ignitor - from £35

Coils compatable with an MS3X - D585

This is the Yukon version, so its the coil with an increadable high power output. It can be directly controlled with an MS3X ECU, or any ECU with a 5V spark output, as it has a built in Ignitor.

The coils come with a 250mm long (8mm) HT lead, meaning they can be mounted on the head, rocker cover, wing, etc, of an older or modern engine.

Image shows a bank on my RV8 running sequential fuel and ignition using an ExtraEFI MS3X ECU

Idea where the Pencil Type COP's can't be used as they don't fit.

Supplied with the connector for the power / control, so everything you need.

Logic level 5V signal to fire unit. 5V starts charging the coil, drop to zero volts and the coil fires.

For wiring info see HERE.


Price: £35

Bluetooth remote wireless comms - £35

No modifications needed, it plugs into your db9 pin connector on the front of the MS ECU, giving the RS-232 port a bluetooth wireless capability.

Fully configured ready for you to use the various app's on your Android phone or Android tablet to tune the ECU and to show dashboard info, etc.

Suitable for any MS ECU except for the early V2.2 boards or those with a micro USB port. If you have a V2.2 then you will need to add a couple of wires internally to give the bluetooth unit a 5V supply.

The MS1 has a different baud rate to the MS2 / MS3, so if you want to use it on an MS1 or another baud rate please Email me before buying and I will sort that for you.


MS1-2-3 main wiring looms - from £60

These are included with an ExtraEFI ECU, so you do NOT need to order one if you buy an ECU from ExtraEFI.

But if you need a wiring loom for your MegaSquirt, then these are supplied with bare ended wires ready for you to wire to your setups connectors.

The looms are approx 1 meter long with a high quality, screened cable for the trigger signal and multiple 0.5mm ground cables for good noise separation.

Each wire is colour coded and has a label with it's description on it that matches the ExtraEFI diagrams.

As the wiring looms are made to your setup requirements, please contact me with all your details before ordering.


Coolant/Air temperature sensors - from £19

If your engine doesn't have both temperature sensors then it is possible to use a sensor from a scrap yard. But some people like to use the original MegaSquirt sensors as these are the sensors that are used as default in your MegaSquirt ECU - GM

The open style air sensor is ideal for fast changing temperatures from boosted engines. The closed style is ideal for coolant and air temperature sensing in most NA setups.

The thread is 3/8" NPT.

Each sensor is supplied with the connector ready to be crimped / soldered to your loom


MS2X Expansion Board for MS2 ECU's - Sequential 4cy - from £12

Adds 2 Injector drivers, cam input, BlueTooth comms, Inputs / Outputs to an MS2

For more info see HERE.


Price: £25

USB - RS232 adapter - £25

Having tested lots of these adapters I have found this type works fine on various laptops, suitable for all MegaSquirt ECU's.

The driver is available here if you need it.

See here on how to setup an RS232 adapter.


Bosch injector style plug - from £20

This is the standard injector plug used on most vehicles using Bosch style injectors as found on Fords, RV8's, etc.

Each item comes with a rubber boot and 2 crimp terminals for the cables, for best results are to solder the wire to the crimps after crimping.


  • 101.5mm diameter - £30
  • 171.5mm diameter - £30
  • 209.5mm diameter - £35
  • Rover V8/TVR crank pulley with crank sensor bracket and VR sensor - £115

36-1 Trigger wheels -from £30

Wheels are lazer cut 3mm thick, 12.7mm diameter hole in the center and 8 radial aligning slots.

The Rover / TVR wheels are specially made to fit the various versions of pulleys that have been

fitted to the RV8's over the years. To ensure we supply the correct wheel / bracket, we require

a picture of your pulley. So please email me


Price: £8.75

30A Relay and base with 3 fused outlets - £8.75

This is ideal for wiring the power to the fuel pump, idle valve, injectors, ignition, etc, so that your ECU controls powers them up with the fuel pump.

This means wiring it into the fuel pump output, see here for a diagram. With 30A of control, it can feed most items that the ECU controls.