Loss Of Power Cuts Off When Stopped

Hi I have an 04 Trailblazer that I purchased new. This vehicle has been great with no major problems until recently when it just turned off when stopped at a red light. I restarted it with no problem but now it will turn off occasionally only when stopped. The main problem that seems to be getting worse is that it seems to have a power lag sometimes and the vehicle will surge and cut back repeadedly while driving. I have remote start and went in a store yesterday and left the car running about 20 minutes while i was inside. When I came out the car was off so I restarted it and it acted weird like sputtering if you will with the rpm dropping and coming back up to idol. I put it in reverse and hit the gas and the car did not respond just kept at idol. It finally moved and surged several times to the point I thought it was going to stall. It has progressively been doing this more I have replaced the fuel filter and air filter.
Does anyone have a thought on what I should replace to maybe fix this issue because i plan on doing the work myself because i am mechanically inclined. I am thinking of replacing the mass air flow sensor is this a good idea and if not what else could cause my problem????:banghead:

You need a full scan for starters to look at the pedal sensor, tps, check fuel pressure and look for pending codes. Many things can cause this but these are the preliminary steps.

i almost had this same similar problem in my eagle talon. everytime i stopped it would shut off on me. i could not find the problem till i took it in turned out to be i had bad spark plugs. who knows might be your same issue, check it out.

bad spark plugs?:confused:

how many miles does it have?? if close or over 100k, then i suggest a small tune-up. i had rough idle issues and it got to the point where it stalled on me
if close to 100k, try changing the
spark plugs, air filter, fuel filter, clean tb, and run a bottle or 2 of techron (it helps). try cleaning the MAP sensor as well, that helped out some people with stalling/idle issues.

The map is a closed sensor it cannot be cleaned, may you meant the maf, which the TB does not have.