Ok this isn't about hot rods but concerns my daily driver. I have a '01 Chevy 1500 4x4 SB V-8 SLT. The truck has about 110 K on it. Since new I have always had it maintained, I never worked on it just had the dealership or shop perform the neccesary work and my company paid for it as routine cost of doing business.
About a month ago the muffler (and tailpipes)finally rusted thru. I took the truck to the dealership for an estimate almost $450...yikes! So I went to like Midas and a couple of other muffler shops...way pricey IMO. My bro-in-law has a '03 GMC 1500 and a couple of years ago replaced his exhaust system with a cat-back dual pipe system for under $250 that he bought from LMC Truck. So that is what I did also.
I have had it on for about two weeks now, it runs fine and sounds good also. Yesterday I went to the store and when I restarted the truck the "Service Engine Soon" light came on and stayed on steady. I checked the idiots manual and of course it gives two scenarios both ending up with see your dealership and talking emission controls, etc. I'm not much of a mechanic especially on vehicles newer than mid '70's...once I couldn't see the valve covers when I opened the hood I knew better than to try and mess with anything unless I had someone knowledgeable guiding me

With all the computer controls etc on newer vehicles I'm wondering what I should do now? I don't want to ruin something on the engine.

Any thoughts or ideas ould be appreciated

Gary