'99 Troubles - Suggestions?

[rpbelize]

To give some background, I live in a developing country, so finding reliable mechanics is challenging at best. I am rather illiterate when it comes to maintaining vehicles, besides the fact that I can do the basics, like change the oil, air filter, and such. I really need some help figuring out what the problem might be, even if I can't fix it, at least I'll have an idea to talk to a mechanic about.

The truck is giving all kinds of grief. Basically it is losing power, especially when driving slow (most of the roads are very rough unpaved, so I take it easy). It sounds loud on startup, and seems to idle rough and high. Then it takes a while to get running smooth. It almost seems like the cylinders don't all kick in. At this stage it will start cutting out, and sounds kind of like a toy engine. The engine will rev up and down on its own, if you stop and let it try to kick in. It may die. Usually, if you shut it off and restart, you get a surge of power. Eventually it seems that all the cylinders kick in it will run fine at higher speeds until you slow down, stop and go, and such. This will bring on the hesitation, loss of power, and shutting down again.

I had the spark plugs changed, a couple oxygen sensors, the air filter, and just recently I changed the MAF.

I checked the codes, and it is showing the following:
P0452

P1132

P1152

Any ideas?

Thanks in advance!