mjdean

My wife's 2009 Suburban has 142000 miles on it. We bought it used about a year ago. It runs great, gets 21mpg avg on the highway, doesnt smoke or leak. The check engine light has been on for some time and I have kind of ignored it because we have had no issues, and just havent had time to mess with it. The codes it is throwing are, P1175 Manufacturer Control Fuel Air Metering, P3400 Cylinder Deactivation System (Bank 1) and P0106 MAP/BAR CKT Range/Perf. I replaced the MAP sensor the other day, cheap and easy way to see if that would fix the 0106 code, and it did not. Also, while driving on the highway, when we are going between 65-70 (this is when I notice it anyway), the vehicle will go into v4 mode, which is obviously normal, but when light throttle is applied, still in v4 just before it goes into v8, it will sometimes cause a rather load thumping sound, almost sounds like cylinder compression possible. Like I said though, the thing runs great and it doesnt always do it. I have noticed that there has been a few times that the v4 mode has never engaged until the vehicle has been turned off and started for the next trip. The Stabilitrac Deactivation message pops up just long enough to see it, at random times. Seems to do it more on rough roads but has also done it on smooth roads. There is no indication of decreased power or anything when this happens. Maybe someone can shine some light on any and all of these issues. I appreciate the help!