Help, I'm a shade tree mechanic who is out of his depth. I have a 2000 Chevy Express van which developed the following problems a week ago; speedometer hand started waving at speed and then at a stop it fluxuated with the RPM, started bucking at low speed, backfiring and sputtering. When I start the van the engine idle increases, decreases, increases, well you get the idea. I plugged it into a computer and received the following codes. P1404, EGR (EGR# 2) closed position performance, P0121, TPS (switch A circuit range/performance problem. I replaced the TPS (new), no change, I cleaned the EGR, no change. As I am stationed in Germany I don't have the luxury to go down to the dealership. Does anyone have any ideas out there? I thought about the O2 Sensor but it didn't show up on the readout as having a problem.

 

Check the spark plugs and spark plug wires.

 

Is there any difference if you unplug the egr valve/s.

 

perhaps your spark plugs has the problem....defects on spark plug wires can hardly be detected, so it is recommended for you to examine or replace the spark plugs at regular intervals or at every 30,000 miles of distance traveled. my friend got his chevrolet pickup spark plug wires replacement...proper replacement is part of your vehicles tune-up.you better have a reliable one!

 

had same prob with mine also speedo jump all over changed trany sensoron tail of trany and that solved it hope it works