2002 Buick Century 1400 to 2000 RPM idle. No DTC shown.
2002 buick century 150Kmiles. Intermittent problem. It seems to happen only after car has been driven for a while. Idle goes to 1400 to 2000 RPM. Have no trouble code. TPS shows varying %'s corresponding to RPM. What could be causing this? Can you recommend a scanner that could show input and output voltages from individual sensors such IAC, TPS, MAF, MAP etc. Price range around $500.00 Thank you