Ok just bought this 00 Si back in Dec after a two weeks it put out a CEL code P0172 Fuel System Too Rich. The spark plugs are all black I need to check out my fuel press. regulator, the only way I know how to check it if it is working is to pull the vacum hose and the motor slighty revs higher which it dones. Did a full tune up on it cap, rotor, plugs, wires, ect. Since then I have cleared the code that was in Mid Dec. But that is not my main Problem. Two days ago I was running it hard to its Red line, when in third gear my car started to stumble hard around 7K, CEL came on at first I thought it was the P0172 code again so I just ignored it at the time. Yesterday my Oil light would turn flash on when I made turn, I figured since my last oil change I put almost 4,000 miles on it. So I put one quart, checked the dip stick, still low. I add another quart, still low. I am leaking no oil. I pulled out my plugs, no oil on them. I also checked my water and it is clean. So I decided to pull the codes again, this time 2 codes, agian the P0172, but now with a P1259 VTEC System Malfunction. I assume the VTEC prob is because of the low oil press. So where the hell is my oil going, if I were burning it wouldnt that throw a diffrent code? If I am burning up oil could that cause the P0172 rich mixture? I really dont want to test out if my VTEC is working. Other then this my car does not smoke at all. It ides just fine, and runs as smooth. It doesnt eat gass or anything.