My concentrater wont stay running - Invacare Supply Group Invacare XPO2 Portable Oxygen Concentrator - Supplemental Battery Pack

Vacuum or incorrect air fuel ratio .also if you moved the butterfly inside the throttle body you will need a throttle position sensor .

I’m happy to assist further over the phone at https://www.6ya.com/expert/joseph_cfbe9ad29efdc8bb

Check the alternator! It may be bad!

need to get trouble codes

Wont stay?? cranking or running? Assuming it cranks but wont stay running I would be suspect of a Crankshaft Position Sensor

Check your security light on the dash and see if it stays on or blinks with the key in on position. If so google how to reset the security.

Check fuel pressure if good, inspect injectors

OK lets start with this..

I am guessing that when you say possion you are meaning you gear selector and when you put it in say drive.

If that is the case.....

Your problem is most likely the fuel pump relay or fuel pump itself.
Start with checking, or have it checked, the fuel pressure at the fuel rail.

If the pressure is low then a fuel pump can be suspect. There are then other test which have to be performed to see where the exact problem is.

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/sean_54c3a3dc48a7773c

throttle is set low, or you may have a fuel pump going out.

Use a gage and check proper fuel pressure. With tbi fuel injection, the fuel pressure is 9--13 psi. I have seen fuel injector spray pattern that looked good to me, but, the fuel pressure was half of what it should have been. 5 psi may show a good spray pattern, but, it won't start and run a v8. In my opinion.
Any applicable trouble codes? Your obd1, you should be able to check some codes yourself, if there are any.

check your tps it may have gone bad. had that happen to a friend changed out the tps and when he cranked it it stayed on hope this help u out let me know