Rough idle

2005 CHEVROLET TRAILBLAZER
156,000 MILES • 4.2L • 6 CYL • 4WD • AUTOMATIC
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.
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RASMATAZ
  • CAR REPAIR CONTRIBUTOR
  • 75,992 POSTS
Do you have a check engine light?

Try cleaning out the idle air control valve, and check the TPS/MAF/MAP sensors
Jun 23, 2020 at 12:45 PM (Merged)
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BRIAN 1
  • CAR REPAIR CONTRIBUTOR
  • 1,030 POSTS
do you know which cylinder or cylinders missfiring?SES light on?have you switched coils or plugs to see if the missfire on that cyl changes to another cyl.need more info.02-06 envoy and t-blazer had a very common problem for leaking or stuck intake valve or valves. I've replaced alot of cyl heads on these vehicles. very very expensive. perform a cylinder leak down test to determine if this is the problem,which it sounds like.
Jun 23, 2020 at 12:45 PM (Merged)