Got a 98 blazer w/a P0420, and... no exhaust leaks, converter good, both O2'z good, wire checked good(wiggle tested w/olm meter), new plugs,wire,cap, rotor. All parts are ac-delco for safe measure. I have read 420 explained, and MY Question Is... has anyone ever heard of a restricted fuel injectors, a bad injector base(were line enter manifold), triggering the P0420 code?
I only ask because all other dtc and misfire monitors are good, and I still feel at idle, with my hand on the end of the open door, a 'micro-miss'(re-occurring stud-er in the engines rotation, that is Not a dead miss) I also notice the fuel system looses all primed pressure as soon as 'key off'.(Making 3-4 key cycles needed for short crank times)
Anyone heard of fuel systems setting off 0420?
Or what causes the fuel pressure to bleed off?
Or if anyone has posted a successful P0420 repair story?
Please n' Thank You for your input