Newbie
Thread Starter
5th Gear
Joined: Aug 2019
Posts: 5
Likes: 2
Newbie
I am new here and new to the Corvette world. Bought a 50th-anniversary car with proxy 60Kmiles on it. I can't get it State inspected because of the misfire code 307 came up. When fixed the 306 came up...and now I am getting 300. I have no mechanical skills so I am fully relying on the mechanics. I am in need of someone that understands what is going on and is willing to help me out. I am in the Houston area. Other than that I love the car!!
Burning Brakes
Joined: Jun 2017
Posts: 760
Likes: 242
From: All Over The Place
A quick search on P0306 (Cylinder 6 Misfire Detected) indicates most likely the following:
"This type of code may be caused by a fuel delivery problem (ie. bad injector), a large vacuum leak, an exhaust gas recirculation (EGR) malfunction, or mechanical engine failure, but is most often the result of an ignition system defect resulting in a low or no spark condition (#6 coil/plug/wire/or combination thereof).
"This type of code may be caused by a fuel delivery problem (ie. bad injector), a large vacuum leak, an exhaust gas recirculation (EGR) malfunction, or mechanical engine failure, but is most often the result of an ignition system defect resulting in a low or no spark condition (#6 coil/plug/wire/or combination thereof).
Safety Car
Joined: Jan 2004
Posts: 4,776
Likes: 142
From: North of Atlanta GA
St. Jude Donor '05
I am new here and new to the Corvette world. Bought a 50th-anniversary car with proxy 60Kmiles on it. I can't get it State inspected because of the misfire code 307 came up. When fixed the 306 came up...and now I am getting 300. I have no mechanical skills so I am fully relying on the mechanics. I am in need of someone that understands what is going on and is willing to help me out. I am in the Houston area. Other than that I love the car!!
Administrator
Joined: Mar 2001
Posts: 367,285
Likes: 24,572
From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03 thru '25
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
Moved to C5 Tech.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,317
Likes: 3,927
From: Cape Coral, Florida
Congrats on your purchase and welcome to the Forum !!...I guess since a shop will be diagnosing this issue you're completely in their hands...I hope they are good at diagnostics or you may be running up quite a bill....one misfire DTC can sometimes set other misfires...this misfire can be ignition related (plugs, wires, or ignition wiring...not so much the coil packs)...fuel (injectors and or it's wiring), mechanical (valve springs,valves,compression etc) and BTW there is NO EGR valve on a C5...just don't want bad info put out !!
Last edited by C5 Diag; Aug 20, 2019 at 03:10 PM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Thread Starter
5th Gear
Joined: Aug 2019
Posts: 5
Likes: 2
So....the guys that have worked on the vehicle seems to have diagnosed the misfire. Changed the plugs and wires as recommended. Ran a fuel clean up...and it seems to have worked. fingers xssed.
While doing it, they offered to also change the battery which seemed to be low in power. done....
Engine runs and sounds great. In low rpm and high rpm....however....something triggered the security problem (shuts down at 2mph!!) so basically the car is stalled at their shop!! I was looking around and this seems to be a common issue when battery is exchanged. I already orderd a LCM5 C5 as it seems to solve the issue.
It really sucks not to be mechanic proficiency sometimes!!
While doing it, they offered to also change the battery which seemed to be low in power. done....
Engine runs and sounds great. In low rpm and high rpm....however....something triggered the security problem (shuts down at 2mph!!) so basically the car is stalled at their shop!! I was looking around and this seems to be a common issue when battery is exchanged. I already orderd a LCM5 C5 as it seems to solve the issue.
It really sucks not to be mechanic proficiency sometimes!!
