have had a loss of power on my 94 non-supercharged previa. acceleration is anemic and when it does finally get up to speed it will sporadicly shudder between 50 and 60mph. engine idle is fairly smooth, not great, but not bad. the vehicle has had the fuel pump replaced,distributor,spark plugs and recently a new catalytic converter and denso oxygen sensors were added. i have cleaned the throttle body and egr valves so those are done. any ideas on what could be causing this? thanks.