Suzuki Forenza wagon


This question is concerning a 5-yr old (not sure of the year of make) Suzuki Forenza wagon (odometer: 52k). Generally the car runs fine, but in the last couple of months I’ve noticed an erratic behavior. On starting the engine, the car will idle for a few seconds before shutting down. Then it takes several start-up attempts before it’ll remain in idle or allow us to drive. This is not predictable or very frequent occurrence, but it happens often enough to cause the owner/driver considerable anxiety when getting into the car. An independent mechanic told me that his sensor will not read this car’s computer, because the computer has either been replaced, or it’s settings altered. Only a dealer can read the car’s computer, and we don’t have a dealer nearby. He thought it might have something to do with the idler sensor or TPS. I don’t know much about this stuff, and I was wondering if anyone out there might have some advice or suggestions.