Need Help!!!! Recently purchased a 1998 Boxster with 114K miles on it, Love the car, fun to drive. Bought knowing it was a project car. Here's why I need help, Started the car pulled out of the garage, put the car in 1st gear and the car began to misfire and making a clanking noise. And of course the CEL light came on. Pulled back into the garage and shut the engine off. The misfire I suspected a fouled plug or dirty fuel filter so I replaced them both. And the car started and ran great until I went to back out of the garage. It began to misfire once some force was put on the engine. Let me back up. I put a reader on it and came up with the following codes.
Prior to plug change: P0300, 301, 302, 302,&341
After plug change: Same as above, along with 1319,1313,1314,1315
Any idea? How bad is it?