P1171 isn't technically "lean under acceleration", it looks to be related to the 02 sensor feedback. Combine that with your misfire code, and I'm gonna ask ya when's the last time you changed out the plugs?

 

Thanks for the reply. The plugs are brand new and gapped to spec. I also put in a quantum fuel pump and new filter at the same time as the plugs. Right now my next planned action is to put in new injectors.

 

Thanks for the reply. The plugs are brand new and gapped to spec. I also put in a quantum fuel pump and new filter at the same time as the plugs. Right now my next planned action is to put in new injectors.

Well dang, don't hear much outta the injectors in these things, I was confident plugs and/or fuel pressure woulda resolved your issue. Diesel running through 'em shouldn't have hurt 'em, it's a "slipperier" fuel after all, but it must have.

 

The engine is 100% stock no mods or ECU tunings.

 

I also tried the starter fluid hack for checking vacuum leaks but got no surge on all the joints I sprayed at between the throttle body and where the intake meets the motor.

Another thought could an O2 sensor just be reading bad but not throwing a code possibly?

 

Another thought could an O2 sensor just be reading bad but not throwing a code possibly?

That's possible, they are just an after the fact tattle tale, after all. Eventually tho, after a few open loop drive cycles, the ECM should trigger a code. But your acceleration stutter is something else, 02 sensor can't cause that.

 

could have messed with the fuel pump regulator potentially, i know when they go bad on our can ams they spit and sputter and you loose performance, cheaper fix if its that.

 

Is that the pc sitting on top of the filter in the fuel pump housing? The Quantum kit came with a new one that I put on this..I think.. hopefully I didn't cross them..

 

not sure how the commander pumps are situated but on the atv pumps yes on top. quantum sells kits with and with out the regulator so im not sure what all you got, atleast there kits use to be like that, its such a cheap little part that all the kits should come with them really especially the XMR mud guy rigs.

 

Yep we are talking the same thing my quantum kit came with one.

 

When you say you replaced the filter, which one are you referring to, the pickup sock at the bottom of the assembly? Or the actual filter sitting on top of the pump?

 

The actual filter on top of the pump. Quantum sells a replacement filter that I put on after diesel gate. So in total I put in a new Quantum pump, sock, filter, and regulator after draining the tank and refilling with 91 octane fuel.

 

So just thinking if I'm looking at the error code correctly the issue is with bank 1 (cylinder 1) and not coming from cylinder 2. And to confirm cylinder 1 is the front one.

 

So put new injectors in and she's off and running like a brand new machine!!! Thanks for everyone's feedback.

 

Ok so running great but check engine light is still on but no active codes. Do I just need to disconnect the battery for a few minutes?

Edit after a 5mile ride tonight the light went off on the next key cycle.

 

Thanks for sharing the resolution, your experience may help future riders

 

not sure how the commanders are but if you check the atvs for codes they ussualy go away after you pull it. theses can ams have electrical oddities and sometimes does require you to disconnect the battery for either 15 minutes to 24 hours. glad you got it sorted out and as Bom said thanks for the sharing the fix.

 

You are welcome!