Hey people. Have owned my sportsman since new and just last ride she started crapping out. Was into my ride about 1.5 hours and it had some severe and rhythmic surging when you try to go past 4500. Idles fine. If you held the throttle steady it would drop to around 1200 and back up to 4500 and down again in about a five second cycle. Would eventually reduce the top rpm that I could rev to , down to 1500 – 2000. Made for a stressful return to truck. Seemed that shutting off for 10 seconds and restarting would help for a couple minutes only. Did all the checks and repairs to wire harness for t-bap, tps, and the little stepper motor. Cleaned out throttle body. All rubber mounts secure. Throttle cable adjusted. Even checked condition of harness to speedo pod. Found the rubber boot holding the t-bap sensor in the intake was shredded. Replaced it. Another ride today was same good hour of ride and the surge returned. At first I had no fault codes but this time I have 22,45,47 codes all sensors nfg at once. Whats the chance of the stepper motor winding in and out changing the mixture and surging . What would cause such precisely timed fluctuation in rpm and power. I even read of the plastic filter thing on the crankcase breather pipe cracking and make surge issue. Any ideas? Thanks

Hey people. Have owned my sportsman since new and just last ride she started crapping out. Was into my ride about 1.5 hours and it had some severe and rhythmic surging when you try to go past 4500. Idles fine. If you held the throttle steady it would drop to around 1200 and back up to 4500 and down again in about a five second cycle. Would eventually reduce the top rpm that I could rev to , down to 1500 – 2000. Made for a stressful return to truck. Seemed that shutting off for 10 seconds and restarting would help for a couple minutes only. Did all the checks and repairs to wire harness for t-bap, tps, and the little stepper motor. Cleaned out throttle body. All rubber mounts secure. Throttle cable adjusted. Even checked condition of harness to speedo pod. Found the rubber boot holding the t-bap sensor in the intake was shredded. Replaced it. Another ride today was same good hour of ride and the surge returned. At first I had no fault codes but this time I have 22,45,47 codes all sensors nfg at once. Whats the chance of the stepper motor winding in and out changing the mixture and surging . What would cause such precisely timed fluctuation in rpm and power. I even read of the plastic filter thing on the crankcase breather pipe cracking and make surge issue. Any ideas? Thanks