My envoy back tires are goin up, so mi car is to high in the back i just went to get a change oil then it is happend they said it is someting like compresor air in the back i dont know noting abot it

are you sure that you put the wires back in the right order?

Try a new PCV valve but it sounds like the engine is tired and has a lot of blowby.

It could be your oil pressure sensor has gone bad.

Did the car drive fine in 2wd? Sounds like you have a different problem with the transfercase. You can run bigger tires as long as they don't rub on the ball joints which may require grinding to make work. Trailblazer/ Envoy owners have put up to 35" tires on there with the same transfer case. Of course with suspension modification, but with the same transfercase and hubs.

Rear end lube should be changed , Timing belt and other belts should be inspected for wear and changed as well...
Most any decent shop will inspect the vehicle for worn out parts when they service it... ( one of the percs of paying someone else to do the oil change). Have them do the free 27 point service inspection...

Change the spark plug wire also. This is often looked over but it has most to do with a miss fire then a spark plug 9 times out of 10

Nothing. Assuming you are doing a 5000 mi interval for oil changes, drive happy until 30,000. At that point do the oil, drain water seperator (diesel only) ck washer fluid, ck brakes (mine lasted until 140, 000 mi), depending on your schedule- rotate and balance tires, and check battery. VW also suggests to pop off the timing belt cover and ck for cracks, fluid leaks ect.

Your big service comes at 40,000 mi. Oh, and if you want to take it to a professional shop, save the money and aggravation and go to a local v-dub, or foreign car specialist. Avoid the STEALership at all costs.... this is from a former dealer tech...

New fuel filter, Spark Plugs & Wires, New air filter.
Tires at max cold psi.
Use a bottle of injector cleaner and change oil every 3k

sound like you need a tune up the light flashing is a misfire take it to autozone and have the codes read