i got a 00 sienna and the motor is misfiring could this be due to the sludge buildup in the v6 toyota motors

My 98 was misfiring as well. I had the injectors and throttle body cleaned. Worked like a charm and it did not cost too much either. Toyota service offers these cleaning as a regular service. Might have been $44 and $66 CDN plus tax. I also changed the plugs, but I think the cleaning did the job.