Just replaced all plugs, plug wires, distributor cap and rotor. When I start the truck it idles very rough for 5-10 seconds, then smooths out. Trouble codes 33(MAP sensor) and 45(Oxygen sensor) now pop up. Will be replacing the O2 sensor today just to eliminate that as a cause. Could either of these sensors be the cause of the rough idle or is there something else going on?

Here are a few things that might help.
1. Check your spark plugs. make sure the gap is right and they are not worn out.
2. Check your distributor cap and rotor for build up on the contacts.
3. Check your spark plug wires, make sure they are on the distributor and spark plug tightly. also check them for damage ie. heat, knicks, scrapes, etc.
4. intake idle control valve. these do cause your symptoms and are easy to replace.

hope this helps ~ Zach

check engine light?? i'd say check the O2 sensors...

Here's the link and I'm sure you will get the solution of your problem
OLDSMOBILE BRAVADA OWNERS MANUAL 1993 2004 DOWNLOAD

check out the idle air control valve and the passages

do u hav the wires on the rite plugs-crosses are common--are plugs gapped rite--get a haynes manual for problems--dirty idle valve questionable

You may have vacum line off or cracked where a try.

1 Inspect Distributor Cap and Rotor Kit Loose, Cracked or Worn Distributor Cap. 1 Inspect Wireset Worn or Damaged Spark Plug Wires. 2 Inspect Distributor Cap Loose, Cracked or Worn Distributor Cap 1 Inspect Condensor-Ignition Faulty Condensor-Ignition. 1 Inspect Timing Specification Incorrect Ignition Timing. 1 Inspect Timing Specification Incorrect Ignition Timing. 2 Inspect Spark Plug Fouled, Damaged, or Broken Spark Plug(s). 3 Inspect Distributor Worn, Damaged or Faulty Distributor.

Try giving it a full tune-up before you try any further (and more expensive) trouble-shooting.

Replace the spark plugs, wires, distributor cap and rotor, air filter (very important), possibly the coil (pricey), and try a bottle of fuel injector cleaner.

If these fail to smooth your idle, then you want to look to the more expensive solutions.

I hope this helps.

I"d lean toward the dirstributor itself. You were right to check the timing but a balky distributor would cause occaisional mis-fires. Apart from that, the timing chain itself would be the next likely culprit.

Had a loose Distributor cap and spark plug. Changed out the plug wires anyway and truck runs great.