It sounds like there is a venting problem with the fuel tank. These tanks have a vent check valve at the top of the tank that normally lets in air as the fuel is being used but in earth working machines this vent becomes blocked from dust and blocks off
SOURCE: 1996 Chevy Express 1500 w/5.0 bogging only when warm.
The cylinder 7 misfire is likely a symptom of the problem, not the problem itself.
Typically, the catalytic converter has an oxygen sensor in front and behind it. When the vehicle is warm and running in closed loop mode, the upstream oxygen sensor waveform reading should fluctuate. The downstream 02 sensor reading should be fairly steady. Typically the P0420 code triggers the check engine light if the readings of the two sensors are similar. This is indicative of (among other things - such as faulty sensors in the "emissions loop") a converter that is not working as efficiently as it should be.
I do not believe that it is a problem with a valve/head gasket or cam.
126 views
Usually answered in minutes!
×