Hi
i am trying to help out my in-laws with their vehicle and it had an intermittent no crank condition. When this happens, usually playing with some buttons on the dash or with the key eventually gets it to start but my father in law did try to start it in park and neutral when this happens and it makes no difference. The thing that worked though was starting it with the oem remote starter although i can’t confirm it works every time because the car has an oxygen sensor heater circuit check engine light so when that is on, the remote start doesn’t work. So in my head i was thinking ignition switch since it worked with the remote starter and yes the recall was done like 6 years ago but a bad ignition switch is still possible isn't it? I looked at the starter and I seen green corrosion on the wires, maybe it could be that but why did it work with the remote starter then? And how do I clean these wires at the starter, the one wire that stays on the starter body is all green from corrosion but when it cranks it cranks fine. Any tips on what else should I check?

 

Welcome to the site, first I would check the basics, tighten the 4 , 7 mm bolts in the under hood fuse box. Then firmly push all fuses and relays into their places. Check the ground wires at the transmission and rad cradle .
the starter photos look nasty , but normal for its age.

 

O2 sensor heater is intermittent? That aims pretty much at loose fuses or wires melting. That is the pressing problem, what is the code, not description?

 

If it works with the remote start when the key won’t work, then you can rule out a corrosion problem at the starter.
Sounds like you may have a key problem. Is the key an original GM one or a replacement ? Have you tried a spare key ?

 

P0053 H02S Heater Resistance Bank 1 Sensor 1

Code is not really intermittent, i will clear it and eventually it comes back but it might take a few miles for it to come back so it doesn't come back right away but when it comes back it stays on until I clear it

 

You don't understand how codes work, that is not intermittent it is a fault.. You need a new #1 O2 sensor, unless there is an electrical problem. Don't get Bosch; NGK/NTK is good.
Turning the CEL off does not fix anything.
Was the ignition recall done? Link in my sig to find out.

 

Seventeen year old car driven in salt. Unless all the external grounds have been re-done, it's a miracle it's running at all.

 

I’m jealous the RS works, I miss a warm car on a cold winter morning!

 

i had replaced it maybe 2 years ago, then got codes for the lower one too so replaced that one but now i wanted to check the heater electrical circuit to make sure its working correctly . Another failed O2 sensor is possible but want to make sure.

 

Choices are: wires, fuses, relays or the sensor.
The fuse is #33 underhood, it also controls the MAF, the EVAP purge,
The relay the crank relay is #34 under hood it ci=ontrols the starter.
The run/crank relay is #51 underhood it controls most everything involved in running the engine and sensors.
The pwr/trn relay runs the ECM, the AC clutch and the EXH fuse (that controls the #33 fuse.
All of this points to a fuse n=box that needs to be re assembled tightly.

Don't listen to this guy, just watch how it is taken apart. Then when reassembling the 4 bolts need to be tightened until all of the blades get seated.