The idiot light popped up on my car. I took it to Autozone (as they have the OBD II reader and I don't want to buy one) and it popped up 4 codes, all codes were related to the PCM sensor for the crankshaft. Has anyone replaced this before. Looks like an easy $40 fix if I do it myself. Any suggetions/recommendations/warnings? I only have 34K on it so this is a huge relief compared to what the other issues could have been. I did a search here on PCM and got nothing. Thanks!