Check eninge light came on and I scanned for codes and found p102,p122,and p171. I have been having a problem with the engine during start up it starts fine then stalls. I restart it and then its fine until I shut it off and then it will stall again. It always restarts and runs fine no other issues. Fuel pressure was 35 when it first started then it drops to about 20 then dies. I restart it and then goes back up to 35 psi. Any help would be appreciated.

P0102 is MAF circuit low input....
P0122 is TPS circuit low input...
P0171 bank 1 lean.. which is probably caused by the low fuel pressure.

I'm wondering if your electrical system is causing havoc everywhere else because the PCM is seeing low voltage at 2 sensors and maybe the fuel pump is seeing low voltage also.

Test power at the MAF connector https://www.gmforum.com/trouble-shoo...2/#post1392523

And test the TPS voltage here https://www.gmforum.com/trouble-shoo...oltage-284385/

i would take care of the fuel pressure first, the stalling could be causing your other codes. whens the last time you changed the filter, pump? you take the vacuum line off the regulator and smell for gas?

I finally bit the bullet and I bought a new Delphi pump and strainer. I put the new pump in on Saturday and the pressure went up to 45 were its supposed to be and it runs great. No more starting issues and so far no more lean codes.

Still don't see how that relates to the TPS, MAF maybe, but still. Thanks for keeping us posted.

alot of times the car give erroneous codes when the engine stalls or you take the battery cable off