95 chev blazer 4.3L Vortec engine troublshooting

service engine soon light flashes or stays on, running very s***ty and sucking up the gas. Have replaced oxygen sensor, cap and rotor, plugs and wires, fuel filter, oil, air filter, pcv valve no luck. What else could be wrong?

The simplest thing to do is get to a decent garage. Have them hook a scan tool to the ALDL connector and read what problems it's having. Most decent places will only charge a diagnostic fee for this. Charles

if you do remove it, buy yourself a piece of like 3 foot long exhaust pipe and have someone you know weld it in place of the Catalytic converter, dont do this if you have inspections in your state, I've heard its a MAJOR fine, here in Indiana we dont have them so.....

So you don't mind breaking a Federal law.

filter, oil,

Federal Law or not, if they had emmission inspections here like they do in all the states around us than probally almost at least 30 percent of all cars would be off the road here.

This engine had two common failure items, both could cause your symptoms.

1. EGR valves plugged. Generally can be fixed by removing and cleaning out the carbon build up
2. CPI fuel pressure regulator and/or fuel line (called nut kit) feeding the CPI unit leaks fuels. Both are located inside the upper manifold. Fix is to replace the CPI unit and nut kit.

I would worry about fixing the DLC first, then worry about everything else.