Hello, New to me 401 Vitpilen, P0301 and rough idle

[allgood57]

Hi there, I just bought a "new to me" 2023 Vitpilen 401 knowing it has check engine light on and trouble at low speed and Idle. It has a P0301 code stored for a generic cylinder 1 misfire. Watching the fuel trims it looks like it hovers at -8% when it's trying to idle. The bike is completely stock and has about 5200 miles. It was in need of maintenance. I've changed the air filter, oil, screens, oil filter, along with a fresh full tank of premium fuel. No change, same fuel trims and behavior. I have a new plug, fuel filter ready to go in when I get time. Tonight is supposed to be the first snow here, so I think the riding season is done for till spring. When I do the plug, I'll check valves and do a compression/leakdown while I'm in there. The rest of the maintenance, brake fluids, chain clean/adjust (maybe replace) possibly fork fluid will be done in the spring time.

Has anyone bought or used the OBDStar scantool? Looks about 330$, HKSP406 Is the part number I'm looking at. It claims it does all the special functions and relearns that a dealer can do too. I'm not sure if it has any added diagnostics for a p0301. I like the look of the FuelX things, but I'm not sure that it would be a band-aid for something else. Maybe I'm reading into it too far.

I have read a couple saying that the dealer can re-flash the ECM? is it a re-flash, or is the ECM pre programed and just a replacement ecu?

Thanks again for any input. I know for a first post this is a bit of a rambling post but I love the look of this bike. I'm not new to motorcycles or vehicle diagnostics, but this is my first Husqvarna/KTM.

 

[allgood57]

I did see the other post about rust in the tank, but this tank looks perfectly clear.

 

[Zep]

I have never had that code but start with the plug and like you say check compression while in there. Could be coil or fuel filter, fuel injector.

What I do know is that a Fuel-x will not solve your problem.

Oh and make sure the fuel lines are not kinked while you change the filter.

 

[allgood57]

I have never had that code but start with the plug and like you say check compression while in there. Could be coil or fuel filter, fuel injector.

What I do know is that a Fuel-x will not solve your problem.

Oh and make sure the fuel lines are not kinked while you change the filter.

I'll add checking the coil to the list. Also, tonight I just realized that the factory warranty may be intact still. The bike was delivered Feb 24'. I don't have a Husky dealer near by, but the KTM dealer 20mi away may work with me. Gotta ask. Thanks

 

[allgood57]

Ok, status report. Warranty is still intact. In preparation for dropping the bike off and having them check it out, I changed the spark plug and fuel filter. I wanted to check off the easy maintenance things first for my own piece of mind. Turns out it WAS the plug. go figure. It looked good, the gap was a little excessive 1.1mm but not to the point I thought would be a problem. I forgot to take a picture, but I'll post one when I get a good view of the electrode. I hope maybe this could help someone, but 5100 miles on an original plug seems like too far. I'll be adding this to the "when changing the oil" list for next time.

 

[troop]

5100 miles on the spark plug isn't even half its service life. A spark plug should be good for much more than 5100 miles. Things can and do go bad early, but it's not normal.

 

[allgood57]

5100 miles on the spark plug isn't even half its service life. A spark plug should be good for much more than 5100 miles. Things can and do go bad early, but it's not normal.

Agreed. A plug wasn't my first thought either. But it was 100% the cause. Replaced it, the fuel trim went right back to a nice and happy -3%LT. Much better than the -13%LT from before. and that was only when I could keep it running stable enough for anything to stabilize. Now, idle settled right in right where it should be, everything is happy. I'll still have to check the valves before riding in the spring, but I have 4 months before that, plus maybe a new set of tires for christmas. Has anyone run the Continental ContiAttack SM2?