QuestionQUESTION: truck stumbles and jerks when trying to give throttle hard to get going, comes up #5 misfire. i replace spark plug, coil, and fuel injector, also the fuel filter. still runs bad will not go over 70 mph
ANSWER: What codes if any are being stored?
2 possibilities:
injector.. this shouldn't cause lack of power, but it may. swap injectors and see if problem follows the injector to the new cylinder.
More likely cause is a plugged exhaust.
Backpressure should not exceed 1.5 psi at 2500 rpm
if it does, then cat is most likely plugged.
For some reason this effects the forward cylinder first
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QUESTION: what causes the converter to plug? No engine lights were on till this happened and its the second time on the same converter
Answer2 most common causes of cat plugging are , if it is melting then there is ttoo much fuel, and if it is plugging, the too much fuel or it is trying to burn oil. The oil coats the cat internals and keeps it from reacting and getting hot enough to burn off.
If you are in a non emmissions area. you may be able to remove the cat, or buy a california CARB cat which is far more efficient and effective.
