Cadillac Repair Questions? Ask a Mechanic for Answers ASAP
Hello I will help you with your question,
These have a problem where the bottom of the boot that connects the throttle body to the intake manifold cracks and unmetered air is dran in.
When you sprayed the brake clean you added fuel to the air being sucked in and it smoothed out.
Not an expensive part ($35) but you have to pull the manifold (1.5 hours) to replace it.
If your mechanic has a scantool that will show fuel trims or O2 sensor voltages they can be monitored when the spray is applied to the bottom of the boot. If the trims/voltages change the boot is leaking.
Please let me know how I can help you with this