Throwing Codes for CatConverters

Ill start by saying that I'm not very knowledgeable about vehicles, but have two close friends who are and will be able to assist me through the process.


I bought a 2004 crew cab with just under 200k miles last week. Seller informed that there was a o2 sensor code see.

Checked it today, and it comes back with both bays cat converter. Here we go. Read most every thread on the subject and contacted u/ nightowl about the cajun resonated b pipes. No emissions where I live.

My dad (20 year mechanic) and mechanically inclined friends are flabbergasted that a cat failure could kill the engine as suggested in multiple threads. Any info on this?

From what I've read, the cause is likely a crack in the exhaust manifold.

It doesn't sound like there's an exhaust leak, but I'm getting the codes no less.

Potentially 2 o2 sensors and the seller wasn't lying? Seems unlikely.

I've put approximately 300 miles on it, speeds up to 90 with no issues, though it does seem to have a small hesitation before accelerating at full throttle, but it's hard for me to estimate any loss of power on a new to me vehicle.

Thoughts on danger w/ driving it? They are encouraging me to drive it regardless as it just got inspected last week w/ the light on... good old boy shop didn't even run it.

"What's wrong with it besides the light being on and fuel economy?"

Thank you all for this great forum. Love the titan. I fully expect to drop the some on the headers and b pipe, just need to justify it to my friends who will be doing the work for a case of beer.