The Lambda (O2) sensor is by far the most common fault that brings up the engine fault light.
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451 Air Box Removal
Want to remove the air box to make something more interesting?
Top Breather Pipe Repair
If your top breather has failed and you are having problems changing it, repair it instead.
Changing Glow Plugs
How to change the glow plugs in your smart fortwo.
Flashing Yellow Triangle
Sometimes you get the traction control light flashing on the speedo, what does that mean?
451 Fortwo Earth Upgrade
Upgrade the 451 Fortwo earth leads
Larger Throttle Body
The original throttle body has a fairly small opening, bigger is better. For the smart 450 and Roadster ONLY. NOT 451.
Oil Sump Pan Change
The sump pan is in a very exposed area so they are prone to damage and rust
451 Coolant Drain
Draining Unless you like to be scalded, wait until the car is cold. Remove the front service panel and undo the cap to the coolant header tank. Look under the car at the engine over to the right. Just behind the long drive shaft, partially hidden by some...
SmartMods HT Leads
Replacement performance silicone HT leads
MHD Starter ECO Fault
There is a new common fault on the 451 MHD that causes the starter to stop working
451 Euro4 Exhaust Retrofit
The Euro4 and Euro5 exhausts are very different but it's easy to retrofit.
Testing Glow Plugs
How to test the glow plugs to see which one is faulty.
450 fortwo Water Pump Change
How to change the water pump in a suprex engine
Roadster Fuel Pump Change
How to remove and replace the Roadster fuel pump
Crankshaft Rotation Sensor
The crankshaft is what the pistons are attached to. The crankshaft sensor measures the rotation of the crankshaft (and therefore the position of the pistons) so the ECU knows when to inject petrol and to fire the spark plug.
45bhp CDI EGR Clean
Diesels are dirty engines, they are noisy but they are efficient. However, if they can't breathe then you aren't getting the best from the engine.
451 Engine Mount Change
The 451 engine mount suffers badly from wear which allows too much engine movement, swapping it is very easy.
451 CDI AC Belt Change
Changing the air conditioning belt on the diesel isn't the same as the petrol model, they didn't put a pretensioner on that belt for you to loosen to enable the belt to just pull off. However, the alternative is actually easier and doesn't require you to retention the belt correctly afterwards.
Petrol 450 Engine Mounts
This is how to change the 3 engine mounts on the petrol 450 fortwo (600cc and 700cc). Side Engine Mounts Remove the bolts from the X-frame on either side and remove it from the car. You can just undo the top bolts and pull the x frame down to get some clearance...