p0131engine lacks power on hard pull chev workhorse 2004 496ci

Question

the vehicle is a bounder motor home with 42000 mi. replaced the fuel filter it was clogged problem still existed. deleted the code and it has not returned. engine still lacks power at 4000rpms up. the fuel pressure is steady at 55psi. towing up hill the unit will almost come to a stop then all of a sudden it picks up and really pulls hard again then it falls back again. what should the fuel pressure be? seems like a fuel problem to me but i dont want to start changing parts until i have some facts. if the injectors are plugging up will that throw a code?

Answer 1

Hi there,

If the code hasn't returned, and the fuel pressure is steady at 55 psi even when driving in these conditions, I would check the catalytic converter. If the substrate is loose inside the converter, it might be blocking the exhaust creating back pressure under heavy load.