I have an '07 Silverado (new style) regular cab shorbed witha 4.8 litre "C" engine. Of course it is untuned yet, I can't wait! It has 700 miles on it so far, already Mobil 1, lost the spare & tools, catback exhaust, and cold air intake.
My transmission is acting as if it's very badly broken. It slams EXTREMELY hard on the upshifts while cruising. I don't mean "good" hard. I mean it feels like a freight train rearended me, and can almost cause a concussion. I suspect the Mass Air Flow sensor.
Although the truck is not EFILive tuned yet, I would really appreciate some input from those of you with more experience than me with the 4L60.
I came across a used cold air intake from a 2500HD, and forced it to fit. In the process, it appears the MAF mesh part (honeycomb) got dented and slightly damaged. The check engine light keeps coming on, and the codes are
P0171 & P0174 (lean bank 1 & 2). I was wondering (hoping) if this could cause the horrible shifting.
As far as the intake is concerned, at first I thought I overoiled the filter. But there is also the possibility of the MAF damage causing the problem, or the little hose that used to plumb into the stock intake (looks like a PCV hose, I just put a breather on it, I think it still has the check valve).
The problem is intermittent, but seems to be increasing in frequency. Any thoughts would be greatly apprectiated.