Engine code (high Voltage M.A.F. sensor

[lawnking]

I own a 2005 Kodiak 4500 with a duramax 6600 allison trans, with 45000 miles on it. I recently changed oil, filter, air filter, and fuel filters one week later got service engine soon light code machine says mass air flow high voltage, so i cleaned maf sensor and reset. again got same code and now has intermetant power loss and black smoke from exhaust. Any help would be greatly appreciated.

[Mark Rinker]

Welcome aboard!

Do you use a K&N or similar oiled gauze filter? If so, there is alot of information here on the board regarding the oil affecting MAF...use the search function to find out more.

[lawnking]

Welcome aboard!

Do you use a K&N or similar oiled gauze filter? If so, there is alot of information here on the board regarding the oil affecting MAF...use the search function to find out more.

No, i should have been more specific but all filters and fluids are stock replacment GM

[lawnking]

I should have been more specific all filters are stock GM and oil is mobile 1 diesel I am now wondering if a stuck fuel injection control module would give this code.

[DmaxMaverick]

A MAF code does not necessarily mean a fault with the MAF. Most of the codes only indicate a variation in voltages/values that are unexpected for the current conditions. Also, a MAF fault shouldn't cause black smoke.

Your problem sounds more related to EGR or turbo vane positioning servo, either can everything you are experiencing, including the MAF code.

[lawnking]

Thanks for the help, I sent the truck to the shop and they say its an egr valve. my question is can I change the part or is their some special tool or knowledge I might not have.

[DmaxMaverick]

In most cases, it only needs cleaning. Unfortunately, the dealer and many shops, insist on replacement almost every time, and when not necessary. You could do it yourself. If you are handy under the hood, it isn't difficult. Replacement and cleaning procedures are well detailed in the service manual. If you need the manual, you can get a book copy at www.helminc.com ($$), or an online subscription at www.alldatadiy.com (better, at a fraction of the cost, and what I use).

John Kennedy (http://www.kennedydiesel.com) has a more effective and "permanent" solution (after cleaning/replacement). Ring his bell.

[lawnking]

Well I spent the day removing and cleaning my EGR valve which wasn't very dirty i reinstalled it and it still has the same problem, but if I unpug the wire to the EGR it runs fine. can i just replace the EGR stepper motor? or leave it unplugged?

[DmaxMaverick]

That depends on what state you are in, its emissions laws, and your tolerance for the glowing yellow lamp. If you are required to emission test, it won't pass with a defunct EGR. Replace it or ignore it (if it runs well otherwise). Your choice.