Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner
1 - 3 of 3 Posts

2003 chevy trailblazer_ltz
1 Posts
Discussion Starter · #1 ·
I have a 03 Trailblazer LTZ I6 with 150 000 miles on it. I previously had issues with misfires so I replaced the spark plugs and all ignition coils at 140 000 miles. Everything was fine until a couple of days ago. I can now feel again that one cylinder is sometimes having a misfire. The OBD2 reader shows misfire on cylinder 1 but the code is the P300 for random misfire. I checked the coil and spark plugs again and did a compression check. All cylinders have a compression of 150 psi. Swapped coils but the problem stays on cylinder 1. I seafoamed the engine twice no improvement. could it be a injector problem and how do I diagnose that?
Thanks for any advice in advance and than you for all the great information you guys have. This forum helped me out many times already.
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.