Winner74
Junior Member
I have a 2001 Dodge Ram 1500 with a 5.9 with 264,000 miles that I have owned since new. It has developed back firing through the intake, rough idle, backfiring on acceleration. I replaced both O2 sensors and it helped but problem returned. I put a spark tester on the coil and the spark was orange. I replaced the coil and 95% of the problem went away. Slowly the problem has returned and the new coil spark is orange and as it jumps the spark checker gap the spark hits intermittently on the other side. The computer, the crank position sensor and the ignition sensor under the distributor cap have all been replaced. The plug wires do not seem to be arcing when I check with it dark under the hood. Any ideas what would cause this problem. New coil went bad (orange spark, within a few days. Unfortunately I didn’t check the spark of Theo. new coil when I installed it because the problem pretty much went away. Thanks for your hel