hi guys, new to the club, hope you guys can help. i have a 92 LS 400, miles are 108,000, the check egine light stays on, i have ran the codes and they come up 25 and 71, 25 says car is running lean, 71 says EGR malfunction, i cleanded the EGR out and replaced the air filter, but still the codes keep coming back after i reset them, any suggestions? roy.