2000 Bravada won't shift and has no power

[cpowell28570]

I was driving the other day and suddenly my check engine light came on. Shortly after, my transmission dropped into 3rd, then to second. My engine didn't want to get above 3000 RPMs. I could get the trans to shift if I took my foot off the gas but would soon drop to a lower gear again. A friend of mine hooked it up to a good snapon computer and it was reading a MAF code. He thinks that this could be the problem but before throwing parts at it I wanted to get some opinions.

[01OldsIntrigueOwner]

What is the engine light code that was pulled up? It could also be the throttle position sensor. When did you change your engine air filter last? A dirty filter can cause the MAF sensor to get dirt on the sensors causing a bad readout.

[woodyBR549]

Clean the MAF sensor. RPM's won't go over 3k? Is that in Park or Drive? Three other sensors can cause this by themselves or in combination with another. The TPS can cause idle and shifting(up or down) issues. The MAP(not MAF) sensor can cause no start and gross power loss. But the VSS will cause shifting or not shifting issues as well as speedometer hopping around, on some models.
From your description, I would be looking at the TPS AND the VSS sensors. in that order.