My truck presently has a P0306 code, diagnosed by the chevy dealer. on 2005 Chevrolet Trailblazer

When the engine light 1st came on, I checked my gas cap and it went off. It came on again and I checked the air in my tires and put higher grade gas in my truck and it went out. A few days later the light came back on. I again checked my gas cap and tire pressure but, the light wouldn't go off. Yesterday, I took my truck to dealer and was told that code P0306 was given. Rather than treat the code, I was told that the additional tests were needed requiring that the intake manifold to be dismantled for further testing of the fuel injector and to perform an engine compression test for additional $400. Is this the norm?

Asked by for the 2005 Chevrolet Trailblazer
yep. sounds right. the gas cap and tire pressure had no effect on your light. you have issues with an injector and have no other recourse.

Hello Mastertech6371.

Will adding fuel injector cleaner to gas help?