Dear rzh,

Hope you're well. If the RPM sensor is original, it does not owe you a penny. To be 100% sure (instead of 99.9999% sure), have someone wiggle the harness, as you try to start the engine. If wiggling allows a start-up, then the harness has failed. The harness is integral with the sensor head, so the entire unit needs to be replaced. An RPM sensor should cost US$35-40.00, in North America.

The EGR systems rarely malfunction. Before I probed that, I'd clean the Idle Air Control Valve (IACV). See the site's FAQs for the proper procedures. If that doesn't cure the low/surging idle, then post back.

Further, once you've cleaned the IACV, re-check the codes. If the EGR code persists, disconnect the negative battery cable clamp from the negative battery terminal (make sure you have the radio security code). Cutting power to the entire car should clear any codes. If the EGR Code returns, please post back. Sometimes, codes are set by a transient condition. When the code is cleared, it does not return.

Hope this helps.

Yours faithfully,

Spook