My 2003 CTS vibrates pretty bad at idle speed (around 600 RPMs) But If I rev up to 800 or so, it's totally smooth.

The real problem is partially due to worn motor mounts, but I dont want to spend $500 to replace them right now.

So, is there any way for me to reprogram the idle speed? Would I have to purchase some aftermarket chip?

2 Answers 2


Aftermarket tuners/PCM flashers (such as HP Tuners) will allow you to do this. However, HP Tuners costs about $600, so your best bet would be to find a friend or shop who already has one, unless you see yourself using such a tool often.

Also, worn motor mounts will put more stress on other mounts in the driveline (transmission, rear diff, etc.) so it might be smarter to just change the mounts.


On some vehicles the Throttle Position Sensor can be adjusted. You can loosen the screws and gently move the TPS until the idle speed changes. I do not recommend doing this.

  • Your recommendation is a good recommendation. Don't do this unless you really know the ramifications. Commented Jul 23, 2015 at 16:26

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