I just picked up an 89 hf with a 91 si motor in it and its throwing two codes. I get a 12 and a 17 with the engine running. I looked up the codes and it showed the 12 as an egr problem and the 17 as vehicle speed sensor. My factory service manual doesn't even have "egr" printed in any of the 681 pages and isn't the speed sensor just the speedo cable going from the diff to the gauges? I've looked the entire motor over and can't find anything resembling an egr valve or a missing egr valve. The speedo cable is installed correctly as far as I know. I was told it's using the si ecu and the stock d15 injectors. It runs fine, doesn't start up as nicely as it should, but idles perfectly and revs hard. Is there something I'm doing wrong?