Well I got the new (Throttle Position Sensor) installed and my 89 TBI K5. My idle problem seems to be fixed. Prior to replacing the TPS, my K5 would not idle up when first started, it would stay at a low idle even if it was a cold start thus creating stalls until the engine warms up. At first I thought it was the o2 sensor so I replaced it but it didn't fix the problem. I checked the ECM for trouble codes and got a code 21 (Bad TPS) Thats why I R&R the TPS. The sensor cost me $23.00 at Advance Auto (Texas). So far everything is working for now but I will really be able to tell when I drive it tomorrow to work. Oh one more thing, how do I clear the trouble codes from the ECM?