1988 Isuzu trooper 2.6 mileage: 145,000. My fuel injection (ITEC) has a hard starting problem each morning. It idles very roughly. The check engine lamp comes on periodically. Checked and noticed the problem is from the oxygen sensor (sensor not yet replaced). I think I'm not getting enough power from this engine. I'm way over here in Cameroon, West Africa, a little too far from good test equipment.
Obviously, the first thing to do is to replace the oxygen sensor. A faulty oxygen sensor would adversely affect engine performance. In addition, with 145,000 miles a major tune would be in order if not done recently.