Hi, I'm new to the forum, my friend recently purchased a 04 Ralliart 2.4, and since he bought it we've done spark plugs, injectors, coils, fuel pump, fuel filler neck, oil change (Castrol 5w30, mobile 1 filter) and some bushings and stuff for the suspension. The car started and ran until we discovered it needed a new fuel tank, and my friend decided just to let it sit because he didn't feel comfortable driving with that current tank. The other day I went to his house to do an oil change with him, and the car took a little to start but it started. We drove it up on the ramps, and we decided to go eat lunch before we did the oil change. We came back and finished the oil change, we went back to start it up and it refused to start, it cranked but never started. So we decided to push it off the ramps and bump start it, I got inside, pushed it fast enough, dumped the clutch and after the second try it started right up and lots of unburnt fuel smell came out and it was idling okay. The second I tapped the gas revs went down and the car stalled. I plug my scanner in and we get 2 codes for P0123 (Throttle / Pedal Position Sensor “A” Circuit High) and P0223 (Throttle/Pedal Position Sensor/Switch B Circuit High). I diagnosed it and turns out it was a faulty throttle body (as when I test-drove it a couple of weeks before it went into limp mode and threw the same codes). We ordered the new throttle body and cleared the codes, and they never came back, so that was successful. I went back today to help my friend get it started, and we decided to bump start it again. Took a couple of tries but the car started up and was cold start idling and was holding revs. The second the revs started to go down to regular idle speed it started stuttering and eventually stalled. We both have no idea what is causing this hard/no start and we are not 100% sure but it might have a garbage tune the original owner put in it.

Any help would be appreciated.

Thanks