2005 fxstsi is misfiring through the breather and idling rough. Putting a load on the engine while riding it is fine but leveling off it starts backfiring.

Are you talking about a go-cart, or a motorcycle, or a tractor-trailer 18 wheeler? Then OF COURSE, you must IDENTIFY the MAKE, the MODEL, and the YEAR of whatever vehicle you are asking about, if you want any REAL help!

Have you checked for a broken valve spring. Repaired a dodge engine with the same running issue as you have described and it was a broken intake valve spring.

The flashing and rough running is to to a misfire or misfires cause by arcing due to moisture on ignition components. Eventually these misfires can lead to other problems such as damage catalytic converter. Start by identifying which cylinder(s) is/are misfiring. The arching can be reproduced with a spray bottle filled with soapy water. Spray the ignition components (wires, coils, distributor cap...)and look for the vehicle to idle rough. Replace any faulty component.

replace no 2 injector

Could be a dirty throttle body or faulty idle air control valve.
Is the check engine light on ?

did you check the coil it may be bad. for # 1 cylinder. if you can, just replace them all. then you will know everything is ok! but change #1 coil first to find out. try putting some injector cleaner in the tank, or swapping the injector from the #1 cylinder to the #2 and see if the code follows it and let us know.

Misfire is a common driveability problem that may or may not be easy to diagnose, depending on the cause. A misfiring cylinder in a four-cylinder engine is, pardon the pun, hard to miss. The loss of 25% of the engine's power output is the equivalent of a horse trying to run on three legs. The engine may shake so badly at idle that it causes vibrations that can be felt in the steering wheel and throughout the vehicle. The engine also may be hard to start and may even stall at idle, depending on the accessory load (air conditioning, headlights and electric rear defroster, for example).

When misfire occurs, performance suffers along with fuel economy, emissions and idle quality. And, when a misfiring vehicle is subjected to an emissions test, it will usually fail because of the unusually high levels of hydrocarbons (HC) in the exhaust.

What causes a cylinder to misfire? Basically, it's one of three things: loss of spark; the air/fuel mixture is too far out of balance to ignite; or loss of compression. Loss of spark includes anything that prevents coil voltage from jumping the electrode gap at the end of the spark plug. Causes include worn, fouled or damaged spark plugs, bad spark plug wires or even a cracked distributor cap. A weak coil or excessive rotor gas inside a distributor would affect all cylinders, not just a single cylinder.

"Lean misfire" can occur when the air/fuel mixture is too lean (not enough gasoline in the mixture) to burn. This can be caused by a dirty, clogged or inoperative fuel injector; air leaks; or low fuel pressure because of a weak pump, restricted filter or leaky pressure regulator. Low fuel pressure would affect all cylinders rather than an individual cylinder, as would most air leaks. A leaky EGR valve can also have the same effect as an air leak.

Loss of compression means the cylinder loses most of its air/fuel mixture before it can be ignited. The most likely causes here are a leaky (burned) exhaust valve or a blown head gasket. If two adjacent cylinders are misfiring, it's likely the head gasket between them has failed. Also, if an engine is overheating or losing coolant, it's likely the head gasket is the culprit.

Intermittent misfires are the worst kind to diagnose because the misfire comes and goes depending on engine load or operating conditions. They seem to occur for no apparent reason. The engine may only misfire and run rough when cold but then smooth out as it warms up. Or, it may start and idle fine but then misfire or hesitate when it comes under load. Also, it may run fine most of the time but suddenly misfire or cut out for no apparent reason. Intermittent misfires can be a real challenge to diagnose, so let's start with a steady misfire in one cylinder before moving on to intermittent misfires.

Hope this help.

a misfiring engine wont have enough power to sustain a load thats why when you shift it dies.you need to retify the problem first.check for any presence of water in the diesel fuel.Not enough fuel pressure

you haven't said if its petrol or diesel so i'm assuming its petrol since your smelling sulfur sounds if you have a misfire causes could be plugs,leads or ign coil i suspect its ign coil these are common to go.

The air fuel mixture sensor is probably starting to fail. You need to have a simple diagnosis done at the shop and then have it replaced - they are usually not much a reputable mechanical shops. When the motor warms up your air/fuel mixture changes hence the rough idle etc. Hope this helps.