Swapped my $800 parts cannon for a $20 fuel pressure gauge and found the real problem in 10 minutes
I spent 3 weekends throwing parts at my truck trying to chase down a rough idle. New plugs, new coils, even a throttle body, all because a code reader kept pointing me at cylinder 3. My neighbor Sal, who ran a shop in Fresno for 22 years, handed me his fuel pressure gauge and said check this first before you buy one more thing. Turned out the pump was weak and the whole time it was a $60 fix. Anyone else learn the hard way to test before you start swapping parts?