My truck is acting really strange. It keeps losing its horsepower. Every now and then it will kick in and its like I hit a red or green arrow on mario kart. Then when the problem returns the truck will not accelerate whatsoever, as if the rpms just climb and there is no acceleration. Some times it will start shaking if I hold the gas at a steady speed. It's as if the engine has stopped getting fuel. Plugs and wires have been changed, tps checked out ok, I have a check engine code 71 EGR System. I was told the EGR malfunctioning wouldn't decrease engine power. People on here are saying the 3vze is slow, but I can tell the engine is pretty quick when it works briefly as if there is no mechanical problem. I'm sure the timing is set correctly but something tells me timing belt isnt staying tight enough or something. When I redo the cam timing the engine runs well for a while and then suddenly gets sluggish as if it lost tension or something. Could the belt be possibly stretched?

 

EGR malfunction will absolutely cause engine power loss. EGR is old burnt up exhaust gas, that you are plumbing back into the fresh air intake. Less o2, less power. You should take the vacuum line off your EGR valve, and plug the rubber hose. Go for a drive and see if it's better. It could be, however, that you EGR valve itself is stuck open. In that case, you could make a block off plate. Or you could simply remove the EGR valve and the long tube that goes into the intake, cut a piece of an aluminum can to make a block off plate, and put it all back together without the intake tube thing. Drive it again and see if that does the trick.