OEM, AC/Delco spark plugs. The newest part number AC Delco is an iridium plug and is the perfect plug for the I6 4.2 litre
spark plug
The 2004 Trailblazer does not have plug wires. It has a coil pack per cylinder that connects direct to the spark plugs.
A 2004 Chevrolet Trailblazer that has a 4.2 liter engine will have a spark plug gap of .044 inches. The best spark plugs for this vehicle are iridium spark plugs.
If the car will not start...the spark-plug is bad.
.043
AC Delco iridiums
The second spark plug is misfiring. Could be the coil right above the spark plug.
Huh? This would be the 5 cylinder engine? No # 6 spark plug? Or the V8? What year vehicle? Need more info, sorry
Bad plug or something is misassembled.
Your spark plug manufacturer would recommend your replacement schedule.
A swivel on the end of a spark plug socket and then an extension on that will get it out.
Ngk br8es