Chevrolet Repair: Chevy Truck Hesitating/Misfire, distributer cap, oxygen sensors

Question
This weekend I replaced the coil, egr valve. Cleaned the distributer which seemed to have quite a bit of build up for less than a year old.  Did not solve the problem. I then replaced the distributer & rotor as well as two oxygen sensors (did not realize there were 4 and auto part store closed). Truck ran great for two days. Now, it seems to have a cough or sputter sometimes between shifting gears and sometimes while driving on the highway when needing to accelerate.

Should I replace the last two sensors or do you think my problem is somewhere else?

Mike


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Followup To
Question -
I have a 96 Silverado. Vortec V-6 4.3L.

At speeds of between 70 to 80 it seems to cutout or mis-fire. I don't loose RPM's and I don't loose speed. It does not do this while accelerating or when going up hill, just at cruising speeds. It use to do this only when wet conditions.

I got a code about 1 & 1/2 years ago for the EGR valve. I replaced the valve. I think soon after this problem showed up. I got a code about gas cap not sealed right. Reset computer and got the code again. I replaced the cap and reset computer and seemed to stop the code. But still had theses symptoms when wet.

Then I got a cylinder hesitation code and I replaced wires, rotor & distributer cap last summer and it seemed to haven taken care of the problem but only to return this winter. It now does this everytime I drive the truck.

I have also replaced the fuel filter, plugs and used fuel treatment as well. Any Ideas?

I'm going nuts.

Any ideas.

Thanks
Mike

Answer -
There are so many possible items that can cause this problem ssuch as:

1. Any sort of vacuum leak in a vacuum hose and or a slight intake manifold leak.

2. An intermittent faulty fuel injector.

3. An intermittent fault in the ignition module.

4. An intermittent fault in the emissions system (EGR CONTROLLER).

5. Loose and or wet electrical connections at the crankshaft sensor, ignition module, possible hair line crack in one of the spark plugs, and the list goes on and on.

Without actually having physical access to the vehicle, There is no way for me to give you an exact fault.



autohelp

Answer
If it ran great for 2 days then there is most likely a fault as to to much fuel in the exhaust system thus causing the exhaust sensors to become clogged with unburned fuel and or heavy carbon deposits thus effecting the oxygen sensors.

What was the cylinder HESITATION CODE # that you got previously ?.


autohelp