I have the codes to replace both cat's on my MDX. My vehicle is now excluded from emissions testing on my state this year.

I only drive it to tow an enclosed trailer (3500 lbs) 20-24 hours from home on 8 hour stints about 14x a year.

I've had some friends suggest I cut the cats off and get it retuned. Has anyone does this on theirs? I'm curious if it made the exhaust loud, and how was fuel economy.

I'm leaning towards getting OEM headers because I'm more into not modifying anything and keeping it reliable. Only big drawback is I'm assuming the header bolts will be rusted on as I live in New England and have 320k on the car.

Anyone have feedback, I'd appreciate it.

 

I have pre-cat deletes on an 08. There is a slight grumble on cold start, but once the engine is warm there is no obvious difference. No noticeable change to fuel economy either.

btw, the pre-cats are a pain to get to, especially the front one. So, I wouldn't suggest it unless you are prepared to spend a good amount of time removing and reinstalling the radiator.

Lastly, idk what you and your friends know about tuning these vehicles. But, the most common is merely an ecu reflash not a full tune. I've reflashed with ktuner v1.2 as a test and had no noticable improvements, likely due to the 3rd cat and stock j pipe being a restriction.

 

Thanks this is what I was looking for. I was more in favor of replacing them versus deleting.

I know bikes, not cars. So I wouldn't know crap about tuning or flashing these things.

 

which state excludes 2010 MDX from emission testing?

 

MA, after 15 years.