Alright ladies and gentlemen,
I'm reaching out to you for your opinions and some assistance. This is regarding my 03 3.8 v6 So last week my car threw a SES (CEL) with the dreaded P04020 "catalyst convertor efficiency below threshold bank 1" So I started going down the checklist of what could cause it. My local exhaust shop found cracks in both my exhaust manifolds, which we all know is common on the 99-04's. He convinced me to let him reweld both of them instead of replacing them. Well my CEL light has stayed off but my passenger upstream catalytic convertor is rattling and needs to be replaced. Now here's my questions: should I just replace my exhaust manifolds or will the rewelded ones be stronger and last longer? Also as far as replacing the cats go, I found a bunch of options online. I've decided to just replace the whole Y pipe with all four convertors all attached to it. A company called eastern catalytic makes a direct fit replacement for about $480 shipped to my door. I also saw that flowmaster and I believe magnaflow makes direct fit replacements for around $500-$550. With that being said does anyone have any experience with any of these? I figure while I'm doing it I might as well replace the four O2 sensors and possibly the exhaust manifolds while I'm at it. I also plan on running some fuel injection cleaner (stp or similar) through my next tank of gas just to clean everything out before replacing everything. I want to make sure it wasn't a fuel injector problem causing the cat to go bad. Anyways I'm just trying to get opinions before buying any parts. Thanks everyone in advance!!