the unit

I have a 2011 Yukon XL. 5.3L At 300000 I got the miss fire warning sign. Took it to the GM dearler and was told you need a new motor. Can be installed for around $10000.00. Was not too happy about that sooooo. I bought a range AFM disabler, changed the spark plugs ( which 4 of them were badly fouled ) and now have 550000 KMS on the same vehicle with no issues what so ever. Only thing I notice is once in a while it seems to burn some oil rather quickly ...did some research and found I should have bought the AFM disabler sooner. I am a happy camper. I now also have a 2015 Yukon XL denali 6.3 L and guess what. It also has an AFM disabler and there are no issues at all. Even happier!!! DW