1998 Chevy Silverado Catalytic Convertors

5.7 L engine in excellent condition. I live in the dry southwest. At 180,000 the SES light came on. Codes said Oxygen sensors (original) needed replacing.

I usually do most mechanical myself, but went to a reputable muffler shop. He sent me to a near by shop to read computer codes with Snap On diagnosis.

Recommended that I change catalytic convertors also with this many miles, said I would need to do it very soon.

I agreed. Long story short, we ended up changing the Oxy sensors (4 - 2 each side) twice and then going to Delco for all four. The part store was incredible did all this at no additional charge!

Muffler shop has also replaced both convertors twice with Magnaflow (probalbly the same part number). My SES light still comes on and the mechanics with good computers say it is still the convertors - not restrictive enough.

I talked to Muffler guy again, and he said Magnaflow claims they have a solution for newer trucks where this has been a problem. They want to sell the pipes with the convertors already on but a lot more $. He also said another supplier has contacted him and claims they have convertors they promise will take care of this problem. Just replacing the convertors like we have already done. He also said they will do this for no charge to try and earn his business.

Are there any after market convertors that work for my vehicle in your experiences?

I have recently heard stories that some people need to buy OEM convertors that are installed on pipes and you replace them where they bolt on. Costs about $600.00 from dealer for my truck. I paid the muffler guy over $300.00 and he is honest and trying.

However, I am loosing patience and a friend of mine heard my truck pinging while going up a mountain slowly. I assume this is from computer not being able to get proper readings and adjust the fuel mixture.

What do you recommend?