4.3L V6 engine surging during acceleration - Hi, I have a 2001 silverado 1500 2x4 with the 4.3L. Have been haveing a surging issue while accelerating. Code came up to ...

Hi, I have a 2001 silverado 1500 2x4 with the 4.3L. Have been haveing a surging issue while accelerating. Code came up to change the EGR. Changed the EGR and new code cam up (#404) Exhaust Gas Recurculation Circuit? What should I do to fix this? The truck runs great if I disconnect the EGR. I clear the code and connect the EGR back up and it surges again and gives me the same code. Anybody know what my problem is and/or how to fix it. I have performed a complete tune up on the truck and still the same issue. Thanks for you help in advance.

Did you clean out the passages in the intake manifold when you changed the valve itself? They tend to get clogged with carbon.

^^^ what He said.. that is a very common issue on the 4.3L V6 what i would do is pull the EGR back off and spray some brake cleaner in the EGR passages and try and clean them up the best that you can i have heard that pipe cleaners work great for this and i have had people tell me that they start the engine up for a few seconds to blow out the passages.. i have cleaned mine on my old 96 blazer and i sprayed the cleaner in the passages and cleaned them up with a shop rag warped around the tip of a screwdriver. I could not get it a 100% but it made my blazer run great again.

If I take the EGR off and keep it connected and start the engine and rev the engine up and down, should the plunger move in and out if is working correctly?

If the plunger is moving then it is working. If the passages in the in take are clogged up, then the valve is working, but no exhaust gas is being recirculated and it is not accomplishing what it is designed to do.

Found the problem (i think)....The left side cat converter is clogged tight. Going to change them both and will let you know if this worked.

Did the CAt fix the problem?

The 2 new catalytic converters fixed the problem.. I cut the old ones off as close to the welds as i could on both ends with a sawz-all. Then I modified a (2) 2 1/2" in and out connector to make the new ones fit, then installed and u-bold clamps. Cleared the codes and started up and runs 100% better and with EGR connected have not had any new codes. Sound alot better going tru the flowmaster muffler also now that it can breath.

Glad you got that fixed up.

Thanks or all of your ideas, sugesstions and help! Nice to have a place to get help with problems kind of out of the norm.