Hey there, I just joined the forum today and I got a question. We just bought a 97 GMC Suburban 2500 4x4 w/vortec 454 and 230,000 miles on it. I replaced the usual tune up items(plugs,wires,cap,rotor,fuel filter)and the upper oxygen sensor on bank 2 because it was throwing a code. When we bought the truck it had a pretty noticeable hesitation at about 1500 rpm's and up when cold or warm. Now with replacing all that and a full bottle of sea foam to the fuel tank it runs better but still has a slight hesitation at 1500 rpm's or higher but only when warm and runs and accelerates very smooth when cold? I've heard that the distributor's on these wear out to the point that the cam positioning sensor cannot pick up properly and it will not run properly. I want to have it replaced along with a dozen other things that it needs but I don't want to start replacing parts and it doesn't cure the issue. Any ideas? I went to my local parts house and used their scan tool and there are no more stored codes either. Thank you in advance guys.

 

I had the same issue with 2003. I had the intake manifold replaced and it solved the same problem, and many other codes it had. I was told by Chevy that the original gaskets were crush type and leaked in air. the new types, like at Autozone, have rubber gaskets on either side. I would not take it to the dealership as they may put in another defective type. hope this helps.