2006 Cadillac CTS • 115,000 miles

Changed spark plugs switched # 5 and # 6 ignition coils still misfire cylinder # 5. Ran injector kill test. NOTICED slight change in RPM. Bad injector? Checked other 5 cylinders with injector kill test noticed substancial RPM and engine change, I am using a snapon Solis Ultra to check vehicle and run tests.
Billy c
November 20, 2013.

Have you checked spark and compression on the number 5 cylinder yet?

Nov 20, 2013.
Check compression first then do a freeze frame and check values as it could be a maf sensor or any other thing, these are really hard to diagnose Also check fuel pressure and check resistance of injectior. If compression ok and injector ok pull valve cover to see if lifter/follower damage. Injector should be11-14 ohm

Nov 20, 2013.