For years now I have had the "Service Engine Soon" light come on and off at random. It would come on and stay on for days and then just disappear for long periods of time. I thought it was probably just an O2 sensor and ignored it. I noticed no ill effects when it was on and that made it easier to just let it go. Well I just replaced most of my exhaust and thought while I’m there I’ll just replace all four O2 sensors. Well within minutes of firing it up with the new exhaust the light came back on. I got curious and decided I would fix it one way or another. I bought a Bluetooth module and the Torque app for my tablet. Plugged it in and fired up the app and got two errors. P0171 and P0174. These are Bank 1 Too Lean and Bank 2 Too Lean. Upon research it said try cleaning or replacing the MAF so I bought MAF cleaner and gave it good cleaning. After resetting the faults and a quick drive the faults came right back. Next it recommends looking for vacuum leaks. I spent several hours looking and found a few little leaks but nothing that cleared the faults. Finally it says to check your PCV valve. Well I just bought a new one ($2.99) and proceeded to put it in. When I went to remove the little 90 degree rubber fitting I discovered that it was collapsed at the bend and also torn. It actually was a piece of hose bent 90 degrees. Now earlier I posted that I had a small oil leak that I couldn’t quite find the source of. In the FSM it states that a bad PCV valve can cause oil leaks and cause your oil stick to pop out. I checked the oil stick and sure enough it was out. I bought a new GM 90 degree connector ($3.99) and put it and the new PCV valve in. This was now a cast rubber 90 not a bent piece of hose. Faults are gone and oil leak is gone. Car runs noticeably smoother and quicker. Best $7.00 I spent so far.

 

Finally, someone that just doesn't start throwing parts at their car to solve a problem. Good job!!

 

Well I spent the money for the FSM and the Bluetooth Module I may as well use them for their intended purpose. They probably just paid for themselves.