93 Prelude si with H23A1. I replaced my stereo and added an amp, but it worked fine after that. Then I started working on my egr issue. I have removed the egr valve and cleaned it up and tried cleaning the ports. It still hasn't fixed my egr problem, but now I have this happening. Would it have anything to do with disconnecting the vacume on the egr valve and plugging it to keep the engine running smooth? I figured I would disengage the egr valve because it was running rough when it warms up. It fixed this problem until I can remove the intake for a good cleaning. I don't know how this would affect the speedometer though.