I wonder if anyone can help me here... I bought a 98 Rodeo and shortly afterward the CHECK ENGINE light came on. I borrowed the OBDII tool from someone at a Honda dealership and the code was a P0401 which is EGR vavle insufficient flow. I cleaned the valve, the tube the entire pintle assembly, verified proper operation with the dealers tool, replaced my intake manifold gaskets and replaced the EGR vavle and the MAP sesnsor. I discovered that the ECM reads a very high temperature for the IAT (Intake Air Temperature) and the ECT (Engine Coolant Temperature). I disconnect these sensors and the tool should read -38F. The tool reads +34F. When the sensor is replaced with a short it should read 274F and they read >350F. I've checked the harness and even removed the wires from the ECM connectors and the ECM thinks it's +34F rather than -38F. There is definetly 5v going to the sensor and my grounds are good. I've replaced the ECM and it didn't help! Any suggestions?

Prolly a dumb question :smokin: , but did you try a new IAT and ECT sensor? I've seen errors in service manuals before on what readings should be.
G/luck
Joel